Today in class we worked with GPE <--> KE conversions and the formula for Kinetic Energy (KE = 1/2mv^2)
We worked some sample problems solving for height of a vertically launched projectile using the KE it had at the start, and some for finding velocity of a dropped item if given its original mass and GPE.
Next week we'll work with some real-world applications of energy - my favorite is with car crashes, but some others as well; Energy is far reaching in this course.
Thursday, October 28, 2010
Wednesday, October 27, 2010
10-27
Today we discussed observing the moon in the morning for the next few days at least, then we'll start looking both in the morning and in the evening again...
Notes today covered Energy: Stored in forms of GPE, Chem PE, and Elastic PE. We worked with the equation GPE=m*g*h and found that its unit, the Joule, is made of N*m or kg*m2/s2.
We also addressed where the GPE was in the pendulum swinging demonstration from yesterday and the other type of energy involved, moving energy, or Kinetic Energy.
Tonight's Homework: READ p. 128-140
Notes today covered Energy: Stored in forms of GPE, Chem PE, and Elastic PE. We worked with the equation GPE=m*g*h and found that its unit, the Joule, is made of N*m or kg*m2/s2.
We also addressed where the GPE was in the pendulum swinging demonstration from yesterday and the other type of energy involved, moving energy, or Kinetic Energy.
Tonight's Homework: READ p. 128-140
Tuesday, October 26, 2010
10-26
Today we graded homework that was mixed review of momentum and motion related problems, then we had demonstrations relating to types of energy.
Demonstrations:
Gailileo's ball and ramp experiment
pendulum - nose demonstration
conversion of mechanical energy into thermal energy
Tomorrow we'll have some detailed notes on these types of energy, plus review momentum (the problem (#25) on last night's homework was met with fierce opposition).
Remember, if you go out tonight and have clear skies but don't see the moon at your designated time, it's time to start doing morning observations.
Demonstrations:
Gailileo's ball and ramp experiment
pendulum - nose demonstration
conversion of mechanical energy into thermal energy
Tomorrow we'll have some detailed notes on these types of energy, plus review momentum (the problem (#25) on last night's homework was met with fierce opposition).
Remember, if you go out tonight and have clear skies but don't see the moon at your designated time, it's time to start doing morning observations.
Monday, October 25, 2010
New Optional Assignment
Looking to raise your grade? Already doing the moon project and planning on doing a science fair project, but want more? Here you go - this one's easier and therefore not worth as many points.
Find a vehicle that has had aerodynamic improvements made on its most recent model to allow it to go through the air with less resistance and maximize fuel economy, post links to photos of both versions of the car, and write details about how the alterations improve the aerodynamics. (example = new ford focus will have shutters on the front of the car to make air go around car rather than through the engine, as older models did, and the outside of the car is smoother, giving it less air resistance)... OR (example = Car XXXXX's 2010 model tapers down at the back end, resembling part of the ideal teardrop shape, while the same car's 2006 model did not (links to photos of each))
You may comment on this page with ORIGINAL examples (first to post gets points) or on the discussion board on my facebook page. If you have no computer access, you may bring me photos and a description.
Find a vehicle that has had aerodynamic improvements made on its most recent model to allow it to go through the air with less resistance and maximize fuel economy, post links to photos of both versions of the car, and write details about how the alterations improve the aerodynamics. (example = new ford focus will have shutters on the front of the car to make air go around car rather than through the engine, as older models did, and the outside of the car is smoother, giving it less air resistance)... OR (example = Car XXXXX's 2010 model tapers down at the back end, resembling part of the ideal teardrop shape, while the same car's 2006 model did not (links to photos of each))
You may comment on this page with ORIGINAL examples (first to post gets points) or on the discussion board on my facebook page. If you have no computer access, you may bring me photos and a description.
Monday, 10-25
Seniors have homework tonight; read p.141-144,p148(bottom) and work problems p. 147#1-2, p. 149#2-4,6
Freshmen have homework tonight as well; p. 123 problems # 16,17,19,20, 23-27 (some review and some new)
Today we had some momentum and Newton's 3rd demonstrations and notes, and played with Newton's cradles.
If you are doing moon observations, you will notice at some point you will no longer see it in the evening... you may want to switch to morning observations for awhile at that point.
At this point we have covered the following objectives: here
If you would like some extra momentum, forces, inertia, etc. review problems, click here
Freshmen have homework tonight as well; p. 123 problems # 16,17,19,20, 23-27 (some review and some new)
Today we had some momentum and Newton's 3rd demonstrations and notes, and played with Newton's cradles.
If you are doing moon observations, you will notice at some point you will no longer see it in the evening... you may want to switch to morning observations for awhile at that point.
At this point we have covered the following objectives: here
If you would like some extra momentum, forces, inertia, etc. review problems, click here
Friday, October 22, 2010
Friday, 10-22
Today classes expored Newton's 3rd law (action and reaction forces) and got some demonstrations for momentum started; we also went over homework from Thursday night.
Monday we'll have some basic notes on Momentum and do some more fun demonstrations with momentum that we didn't get to today, including everyone's favorite; Newton's Cradle.
Full moon over the weekend, so be on the lookout as long as the weather's nice and it'll be up all night.
Monday we'll have some basic notes on Momentum and do some more fun demonstrations with momentum that we didn't get to today, including everyone's favorite; Newton's Cradle.
Full moon over the weekend, so be on the lookout as long as the weather's nice and it'll be up all night.
Thursday, October 21, 2010
Thursday,10-21
Parents: Conferences will be from 12:20 to 7PM next Thursday, the 28th. Pick up report cards, meet teachers, and get access codes for online grades if you haven't yet.
Freshmen: Tonight read p.113-117. Problems on p.117# 1-6, and p.880, #39-43. Due tomorrow.
Today in class we finished learning about gravity and how to use the Fg = Gm1m2/r^2 equation. We also simplified things a bit and just looked at what happens when the mass of an object is doubled, halved, etc. and what happens when the distance between objects is doubled, halved, etc.
We also reviewed Newton's 1st and 2nd laws, then moved on to Newton's 3rd: Action - Reaction Force pairs. We worked some examples; some involved amusing stuff. Important to know that to find a reaction force, you just switch the objects of the action force in a sentence.
Ex: Action force = Joe's foot pushing on a ball as he kicks it.
Reaction force = The ball pushing on Joe's foot as he kicks it. (equal in size of the force, just opposite in direction). The last thing I left classes with to think about is this:
If action and reaction forces are equal in size and opposite in direction, why don't they just cancel everything out, leaving us with no net forces? The answer? They act on different things. Refer to the examples above; action force was acting on a ball, and the reaction force acts on a foot. Both items accelerate as a result.
Tomorrow we'll have some brief notes on momentum, go over the homework, and do some fun Newton's 3rd / Momentum demonstrations. Not a day you'll want to miss!
Freshmen: Tonight read p.113-117. Problems on p.117# 1-6, and p.880, #39-43. Due tomorrow.
Today in class we finished learning about gravity and how to use the Fg = Gm1m2/r^2 equation. We also simplified things a bit and just looked at what happens when the mass of an object is doubled, halved, etc. and what happens when the distance between objects is doubled, halved, etc.
We also reviewed Newton's 1st and 2nd laws, then moved on to Newton's 3rd: Action - Reaction Force pairs. We worked some examples; some involved amusing stuff. Important to know that to find a reaction force, you just switch the objects of the action force in a sentence.
Ex: Action force = Joe's foot pushing on a ball as he kicks it.
Reaction force = The ball pushing on Joe's foot as he kicks it. (equal in size of the force, just opposite in direction). The last thing I left classes with to think about is this:
If action and reaction forces are equal in size and opposite in direction, why don't they just cancel everything out, leaving us with no net forces? The answer? They act on different things. Refer to the examples above; action force was acting on a ball, and the reaction force acts on a foot. Both items accelerate as a result.
Tomorrow we'll have some brief notes on momentum, go over the homework, and do some fun Newton's 3rd / Momentum demonstrations. Not a day you'll want to miss!
Wednesday, October 20, 2010
Wednesday, 10-20
Today quarter grades were posted. If you want to improve your grade before your parents see it, you have until next Wednesday to do so. I will have all classes' lab books graded by then.
Parent Teacher Conferences are next Thursday, October 28th. We have a half day of school in the morning, I believe school will release at 11:30 (it changed this year from 10:50 in the past), and conferences run all afternoon. I believe the official hours are 12:30 to 7:00pm; I will update here when I have the official information.
Students: The good thing about parent teacher conferences (besides getting a half day and knowing that your parents go to talk to your teachers about how wonderful you are...) is that there is no school on Friday! (the 29th)
Parents: you will be getting phone calls from your child's advisory teacher (not necessarily a teacher of a course they have). If they leave a message, they should include information about conferences and how to call them back, at 636-296-5210 and their extension number. Please call back and let them know you got the message.
The other thing that will be mentioned is grades online and how to access edline; if you don't have a login/password, email hoelzer@fox.k12.mo.us with your name and your child's name, and Judy will get you started.
Today in class we learned about satellites and orbit, and that there is no such thing as "zero gravity" , only situations where an object is in "free fall" and feels weightless. All satellites are constantly falling toward Earth and accelerating due to gravity. As long as they don't speed up or slow down due to an external force, they will remain in orbit indefinitely.
We also learned how to use the Fg = (Gm1m2)/r^2 equation to find an object's weight, and practiced using scientific notation in calculators. Tomorrow we'll emphasize the effects of changing mass and radius on an object's weight, with a bit less math.
Parent Teacher Conferences are next Thursday, October 28th. We have a half day of school in the morning, I believe school will release at 11:30 (it changed this year from 10:50 in the past), and conferences run all afternoon. I believe the official hours are 12:30 to 7:00pm; I will update here when I have the official information.
Students: The good thing about parent teacher conferences (besides getting a half day and knowing that your parents go to talk to your teachers about how wonderful you are...) is that there is no school on Friday! (the 29th)
Parents: you will be getting phone calls from your child's advisory teacher (not necessarily a teacher of a course they have). If they leave a message, they should include information about conferences and how to call them back, at 636-296-5210 and their extension number. Please call back and let them know you got the message.
The other thing that will be mentioned is grades online and how to access edline; if you don't have a login/password, email hoelzer@fox.k12.mo.us with your name and your child's name, and Judy will get you started.
Today in class we learned about satellites and orbit, and that there is no such thing as "zero gravity" , only situations where an object is in "free fall" and feels weightless. All satellites are constantly falling toward Earth and accelerating due to gravity. As long as they don't speed up or slow down due to an external force, they will remain in orbit indefinitely.
We also learned how to use the Fg = (Gm1m2)/r^2 equation to find an object's weight, and practiced using scientific notation in calculators. Tomorrow we'll emphasize the effects of changing mass and radius on an object's weight, with a bit less math.
Tuesday, October 19, 2010
Today's exam
grades will be posted tomorrow, since I opted to make the exam all multiple choice so I could get it graded; I've been behind grading lab books and need to get caught up.
In the meantime, check out this link:
http://www.wired.com/wiredscience/2010/10/top-20-microscope-photos-2010/
In the meantime, check out this link:
http://www.wired.com/wiredscience/2010/10/top-20-microscope-photos-2010/
Monday, October 18, 2010
New material after Tuesday's exam
After the exam Tuesday, we will discuss orbits and gravity briefly (relates back to material on exam, but I didn't get it presented in time) and then move on to Newton's 3rd Law and Momentum/Collisions. We will therefore have a break from difficult math for a few days before exploring energy, probably starting on Friday.
If you want to get ahead, read p. 104-105 and p.113-117.
If you want to get ahead, read p. 104-105 and p.113-117.
Friday, October 15, 2010
Friday, 10-15
Today we explored Air Resistance: force that acts to oppose an object's motion as it moves through the air (or any fluid can resist...)
Depends on:
Density of fluid
Speed of object relative to fluid
Shape of object
Size of object
Demonstration: air resistance in a vacuum: We pumped most of the air from a cylinder and found that a feather drops at the same rate as anything else (like a BB) without air resistance.
Logic problem: We also analyzed a skydiver's motion as they fall from a stop (right after exiting a plane, etc) to when they reach terminal velocity. Acceleration is highest at the start and decreases to zero when they reach maximum speed.
After that we went over the homework from last night and watched videos involving air resistance - a bicycle that goes over 80 mph, new cars' technology for aerodynamics and economy, and guys using wing suits to increase air resistance when base jumping... giving them a lower terminal velocity and allowing them to do some amazing stunts.
A note of caution: Don't confuse the terms velocity and acceleration.
Acceleration is negative when an object's velocity decreases.
Acceleration is not necessarily decreasing when an object's velocity decreases. If you're asked to describe acceleration of an object speeding up, you should answer "positive acceleration", not "increasing acceleration" The acceleration might be absolutely constant, or decreasing, but if it's at all positive, the item involved is speeding up.
Depends on:
Density of fluid
Speed of object relative to fluid
Shape of object
Size of object
Demonstration: air resistance in a vacuum: We pumped most of the air from a cylinder and found that a feather drops at the same rate as anything else (like a BB) without air resistance.
Logic problem: We also analyzed a skydiver's motion as they fall from a stop (right after exiting a plane, etc) to when they reach terminal velocity. Acceleration is highest at the start and decreases to zero when they reach maximum speed.
After that we went over the homework from last night and watched videos involving air resistance - a bicycle that goes over 80 mph, new cars' technology for aerodynamics and economy, and guys using wing suits to increase air resistance when base jumping... giving them a lower terminal velocity and allowing them to do some amazing stunts.
A note of caution: Don't confuse the terms velocity and acceleration.
Acceleration is negative when an object's velocity decreases.
Acceleration is not necessarily decreasing when an object's velocity decreases. If you're asked to describe acceleration of an object speeding up, you should answer "positive acceleration", not "increasing acceleration" The acceleration might be absolutely constant, or decreasing, but if it's at all positive, the item involved is speeding up.
Thursday, October 14, 2010
Thursday, 10-14
Answer key to the review sheet in the previous post: Here
Tonight's homework: read p.83-86 and p.86#1-7
Today in class we explored friction, the force that opposes sliding motion between two items in contact.
We determined:
-Weight, or force between objects, increases frictional force by making surfaces conform to one another and increases microscopic surface contact, which results in more microwelds and more friction.
-Surface area (on the scale that we can see, not microscopically) has pretty much no effect on friction.
-Surface types have a great effect on friction
-water may increase or decrease friction, depending on the circumstances (wiping dirt off shoes, etc)
-Motion is related to friction!
2 types of friction are related to motion:
Static friction: When 2 surfaces are not moving past one another, the maximum amount of friction between them is labeled as static friction.
Kinetic (sliding) friction: When surfaces slide past one another, kinetic friction is experienced. Kinetic friction is lower than static friction.
Your car's Anti-Lock Brakes (ABS) make use of static friction; they adjust pressure to the brakes many times per second to allow for maximum braking without locking the wheels and causing them to slide. This not only allows you to stop faster, but also to steer your car while you are braking.
Tonight's homework: read p.83-86 and p.86#1-7
Today in class we explored friction, the force that opposes sliding motion between two items in contact.
We determined:
-Weight, or force between objects, increases frictional force by making surfaces conform to one another and increases microscopic surface contact, which results in more microwelds and more friction.
-Surface area (on the scale that we can see, not microscopically) has pretty much no effect on friction.
-Surface types have a great effect on friction
-water may increase or decrease friction, depending on the circumstances (wiping dirt off shoes, etc)
-Motion is related to friction!
2 types of friction are related to motion:
Static friction: When 2 surfaces are not moving past one another, the maximum amount of friction between them is labeled as static friction.
Kinetic (sliding) friction: When surfaces slide past one another, kinetic friction is experienced. Kinetic friction is lower than static friction.
Your car's Anti-Lock Brakes (ABS) make use of static friction; they adjust pressure to the brakes many times per second to allow for maximum braking without locking the wheels and causing them to slide. This not only allows you to stop faster, but also to steer your car while you are braking.
Wednesday, October 13, 2010
Wednesday - Friday
Today we graded the review worksheet; I will hand them back tomorrow so you can study for.....
Answers will be added on Friday so you can check back here after you try problems out.
Also today we explored a bit with friction involving different items and practiced using spring scales. We came up with some different independent variables which MIGHT affect friction between surfaces, such as: surface types, force pushing forces together (like weight), wetness, oil, surface area, speed an object's moving, etc. Tomorrow we'll run a lab to test these variables and see which ones do affect friction.
Thursday's homework: Read p.p.83-86; work problems #1-7 on p.86.
Friday we will work with air resistance, working with problems, videos, and demonstrations.
Tuesday, October 12, 2010
Monday and Tuesday, 10-11-12
Monday I was absent; the worksheet posted on Friday's post (see link below) was handed out.
Today we finished inertia demonstrations and I answered questions on the worksheet; it's due tomorrow.
**Optional Assignment** If you are wanting something to elevate your grade, you should be starting Moon observations tonight. Each night (or early morning), you need to record the following: (on any piece of paper is fine)
-(date)
-Time
-Direction you see the Moon (North, SW, E, S, etc...) - ask your parents or use the internet to figure out what directions are at your house.
-Sketch (make it large and detailed if you can see any features/craters)
-Approximate angle in the sky (ex: 25 degrees above horizon)
-Weather conditions (clear, partly cloudy, etc.)
Example of an ideal reading:
10-12
8:15 PM
West, slightly SouthWest
*
*
* (large sketch goes here)
*
*
25 degrees above horizon
Clear skies
When problems arise:
1. )No moon? Just report:
10-12
8:15PM
Cannot find moon
Clear sky
2.) Too cloudy? Just report:
10-12
8:15 PM
Moon is up, but behind clouds
The time doesn't have to be the same each day, but it helps if you can keep it consistent for a few days in a row at the same time during some portion of this project so you can judge motion from day to day. I set an alarm on my cell phone to remind me.
If you miss a day, just make a note of it in your log and skip it.
We are looking for a full lunar cycle, so if you see the Moon tonight, you will take observations each day (or night) until you see the same image in the sky again.
Today we finished inertia demonstrations and I answered questions on the worksheet; it's due tomorrow.
**Optional Assignment** If you are wanting something to elevate your grade, you should be starting Moon observations tonight. Each night (or early morning), you need to record the following: (on any piece of paper is fine)
-(date)
-Time
-Direction you see the Moon (North, SW, E, S, etc...) - ask your parents or use the internet to figure out what directions are at your house.
-Sketch (make it large and detailed if you can see any features/craters)
-Approximate angle in the sky (ex: 25 degrees above horizon)
-Weather conditions (clear, partly cloudy, etc.)
Example of an ideal reading:
10-12
8:15 PM
West, slightly SouthWest
*
*
* (large sketch goes here)
*
*
25 degrees above horizon
Clear skies
When problems arise:
1. )No moon? Just report:
10-12
8:15PM
Cannot find moon
Clear sky
2.) Too cloudy? Just report:
10-12
8:15 PM
Moon is up, but behind clouds
The time doesn't have to be the same each day, but it helps if you can keep it consistent for a few days in a row at the same time during some portion of this project so you can judge motion from day to day. I set an alarm on my cell phone to remind me.
If you miss a day, just make a note of it in your log and skip it.
We are looking for a full lunar cycle, so if you see the Moon tonight, you will take observations each day (or night) until you see the same image in the sky again.
Friday, October 8, 2010
Monday, 10-11
Announcement: We have an exam coming up; we will plan to have it this coming Friday, the 15th.
Monday - we will have more inertia tricks and examples, and you will receive a review sheet as homework - I have been displeased with the amount of individual study happening when I don't assign homework, so homework is going to increase for awhile before I try to let the freshmen study some individually again.
Want to get a head start on the review sheet (due next Wed)? Get it here.
Physics students had a fun day today; we worked with the air cannon and played with some inertia toys. Frst - person video of the air cannon courtesy Ryan B. coming soon; if the video is good enough I will post it on Youtube and link to facebook and here. Physics on Monday will start a cook video on Einstein and have homework; read p.124.131, 134.135 and work problems - p.133#2, p.135#1-3. Hopefully we'll also be able to solve for the initial velocity of the Ryan's cell phone when it was launched.
Monday - we will have more inertia tricks and examples, and you will receive a review sheet as homework - I have been displeased with the amount of individual study happening when I don't assign homework, so homework is going to increase for awhile before I try to let the freshmen study some individually again.
Want to get a head start on the review sheet (due next Wed)? Get it here.
Physics students had a fun day today; we worked with the air cannon and played with some inertia toys. Frst - person video of the air cannon courtesy Ryan B. coming soon; if the video is good enough I will post it on Youtube and link to facebook and here. Physics on Monday will start a cook video on Einstein and have homework; read p.124.131, 134.135 and work problems - p.133#2, p.135#1-3. Hopefully we'll also be able to solve for the initial velocity of the Ryan's cell phone when it was launched.
Thursday, October 7, 2010
Thursday and Friday
Today we went over last night's homework and worked some sample problems relating weight and mass, then we verified the relationship between Force, Mass, and Acceleration from Newton's 2nd law (F = m*a) using the air track.
Physics students found the acceleration of the small, gold(100g) glider to be (almost) EXACTLY 1/3 that of the large, blue (300g) glider; .145 m/s^2 vs. .463 m/s^2
Tomorrow we have extended advisory for a presentation in the morning, and all classes will be slightly shortened.
We will work with newton's 2nd some more, and I will present: Freeman: Master of Inertia!
(just some nerdy science tricks that you can use with your family and friends)
Wednesday, October 6, 2010
Wednesday, 10-6
Today we had notes and demonstrations regarding:
Mass vs. weight
Balances vs. Scales
Adding Forces
Newton's first law: Inertia
Newton's 2nd law: Acceleration depends on mass of object and net force applied... Fnet = m*a
Tonight's homework: Read p. 102-109; Work problems on p. 111: #2,3,5-7
An announcement: CERT members - the training has moved from Friday to tomorrow at 8:30.
Seniors: Fun labs: model airplane lab practical - for practice, not for points, and playing with the air track to prepare for tomorrow - attempting to show Newton's 2nd law experimentally.
Mass vs. weight
Balances vs. Scales
Adding Forces
Newton's first law: Inertia
Newton's 2nd law: Acceleration depends on mass of object and net force applied... Fnet = m*a
Tonight's homework: Read p. 102-109; Work problems on p. 111: #2,3,5-7
An announcement: CERT members - the training has moved from Friday to tomorrow at 8:30.
Seniors: Fun labs: model airplane lab practical - for practice, not for points, and playing with the air track to prepare for tomorrow - attempting to show Newton's 2nd law experimentally.
Tuesday, October 5, 2010
Tuesday, 10-5
Homework tonight: Read Chapter 3, section 3: Forces. (I forgot the page numbers)
Tomorrow we will discuss inertia and more on Mass vs. Weight, play with the air track (gently; it's expensive and fragile), learn to add forces, and how to relate mass and weight mathematically using Newton's 2nd Law. I will probably assign homework to practice.
Thursday and Friday we will learn about air resistance and Friction, and we'll set up an experiment (name your own IV and DV) for Monday involving Friction.
Tomorrow we will discuss inertia and more on Mass vs. Weight, play with the air track (gently; it's expensive and fragile), learn to add forces, and how to relate mass and weight mathematically using Newton's 2nd Law. I will probably assign homework to practice.
Thursday and Friday we will learn about air resistance and Friction, and we'll set up an experiment (name your own IV and DV) for Monday involving Friction.
Monday, October 4, 2010
Quiz tomorrow
Here's the key to the review sheet that was posted a couple of days ago.
I had some people ask, so I decided I will be posting the base equations on the board tomorrow. I will not be solving simple algebra for you however.
I had some people ask, so I decided I will be posting the base equations on the board tomorrow. I will not be solving simple algebra for you however.
Friday, October 1, 2010
Quiz Tuesday
This was announced in class on Thursday, but just a reminder again...
This will cover
speed/distance/time
velocity/displacement/time
acceleration/change in velocity/time
equations for each
graphs for each
gravity on Earth as an accelerating factor at ~-10m/s^2
Want a review sheet?
This will cover
speed/distance/time
velocity/displacement/time
acceleration/change in velocity/time
equations for each
graphs for each
gravity on Earth as an accelerating factor at ~-10m/s^2
Want a review sheet?
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