Friction + Inclined Planes

Today we first went over Friction TIPERs #4 and traded papers to give feedback. That does not need to be turned in.

Later we did one practice problem that combines friction and inclined planes, then you started on your homework:

p.117 #30 & 51
+ complete the pre-lab for our lab tomorrow: Finding the Coefficient of Static Friction

Friction Practice

Today I was out, so you practiced some friction problems on your own. Whatever you didn't finish in class is homework.

Friction TIPERs #3
Friction TIPERs #4
p.118 #39 & 43

Friction

Today we started talking about friction:

Notes: Friction

We completed Friction TIPERs #1 in class; Force TIPERs #5 and Friction TIPERs #2 are homework. Email miss.volkening@gmail.com for copies.

Work Day - Practice Problems

Because of the pep assembly (and because everyone needs to practice more force problems) today was a work day. I checked your labs from earlier in the week while you worked on a new problem set:

p.114 MC #10 and Conceptual #1 + p.116 #21, 24, 26, 29, 38

Practice + Inclined Planes

Today's Bellwork: What was wrong with the setup for the lab on Monday/Tuesday? Answer: we said that the net force on the cart was equal to the weight of our hanging object. That would only be true if the acceleration of the hanging object was zero, which it was not.

This means the actual, measured acceleration was smaller than the math predicted it would be. This effect is more pronounced at smaller cart masses (or larger values of 1/m). This tipped your best fit line for a vs. (1/m) down, decreasing the magnitude of its slope and therefore decreasing your calculated value for the mass of the hanging object.


After that big discussion, we went through how to deal with inclined planes. There is only one major change:



After you tip the axes you proceed pretty much the same as yesterday.

Hopefully you started your homework in class:

p. 117 #27 & 28

Solving Newton's 2nd Law Problems

Today we went through a method of solving word problems that involve Newton's 2nd Law:

Notes: Solving Newton's 2nd Law Problems

We may or may not have gotten to all of the examples, depending on the class. What we didn't get to we will finish tomorrow.

Homework is p. 116 #17 & 25 + what was wrong with the lab setup on Monday/Tuesday?

Newton's 2nd Law Lab

Today we used Newton's 2nd Law to find the mass of an object without relying on a scale.

Newton's 2nd Law Lab

This is another lab where I am checking your notebook, so don't actually turn anything in. Please have it ready to check by Friday, but sooner is also fine.

Challenge: something was wrong with the setup - can you find it? We'll talk about it Wednesday, but it's the reason more mass on the cart worked better.

Newton's Laws Practice

Today is a half day! We worked on three TIPERs; they are homework if you don't finish in class:

Forces TIPERs #2
Forces TIPERs #3  Edit: I'm throwing this one out
Forces TIPERs #4

Email miss.volkening@gmail.com if you need copies.

We will be completing the Newton's 2nd Law Lab on Monday/Tuesday, so bring your lab notebook. Closed-toed shoes are also recommended.

Newton's 3rd Law

We have come to the last of Newton's three laws. There actually isn't a lot to say:

Notes: Newton's Third Law

Homework is Force TIPERs #1 (email miss.volkening@gmail.com for a copy)+ #6-9 on the Forces Non-Textbook Problems.

Here are the free-body diagrams for boxes A and B on the back of Force TIPERs #1:

Tomorrow is half day so we will just have work time with more TIPERs.

Here are some sketches about normal force that made it up onto the board.

Newton's 2nd Law

Today we had a taste of Newton's Second Law:

Notes: Newton's Second Law

Homework:

p. 115 Problem #2
Forces Non-Textbook Problems #4 & 5

Forces and Newton's First Law

Today we started our forces unit with Newton's first law and free body diagrams:

Notes: Forces and Newton's First Law

We worked on a Net Force worksheet in class - it is homework if you didn't finish.

Homework is #1-3 on the Forces Non-Textbook Problems Bank.

2-D Kinematics Test

Today is your second test: 2-D kinematics. Next up is forces.

2-D Kinematics Test Practice

We started today by going over last night's homework together. You do not actually need to turn that in.

You then started working on the practice test for 2-D kinematics; that test is on Friday. While you were working I may have checked off your lab from yesterday.

We are doing the same thing tomorrow.

2-D Practice Test

ABRIDGED Key:

Projectile Motion Lab

Today we are completing the Projectile Motion Lab. Note that this is done completely in your lab notebook; you are not turning this in, but it will be checked.

This is one of the launchers we used - many thanks to the University High School Foundation and Alumni Association for buying these.


Homework is the worksheet Projectile Motion TIPER #2 (email miss.volkening@gmail.com for a copy). We will be discussing the Evaluate Student Answers (ESA) problem tomorrow at the beginning of class.

Finishing your lab is also homework.

Projectile Motion Problems

Today we went through a process for solving projectile motion story problems.

Notes: Projectile Motion Problems

Here is the work for the airplane problem:

Here is the work for another problem in which someone jumps with a speed of 11 m/s at an angle of 20 degrees above the horizontal. We found the time it took to reach max height, the jumper's max height, and the horizontal distance the jumper went before coming back to his/her original height.


Homework is —Ch.3 (p. 80) #23, 25, 27, 29, 30, 47, 48. We'll be doing a lab on Tuesday (no school Monday).

Motion in 2 Dimensions

Motion in 2 Dimensions (Projectile Motion)

I could not get my videos to embed in my Powerpoint - sorry! - so here are links to the ones we saw:

Three Balls Roll Off a Table
Mythbusters Bullet Drop (we actually didn't see this in class because the video was blocked)
MIT Monkey Problem

Homework: Projectile Motion TIPER #1 (email miss.volkening@gmail.com for a copy)