WARM-UP
1. Carlos and his older brother Ricardo are at the grocery store. Carlos, with mass 17.0 kg, likes to hang on the front of the cart while Ricardo pushes it, even though both boys know this is not safe. Ricardo pushes the cart, with mass 12.4 kg, with his brother hanging on it such that they accelerate at a rate of 0.20 m/s2.
a. With what force is Ricardo pushing?
b. What is the force the cart exerts on Carlos?
2. Imagine that you are sitting in a car tossing a ball straight up into the air.
a. If the car is moving at a constant velocity, will the ball land in front of, behind, or in your hand?
b. If the car rounds a curve at a constant speed, where will the ball land?
3. Why is it that a car traveling in the opposite direction as the car in which you are riding on the freeway often looks like it is moving faster than the speed limit?
CLASSWORK
Exam on CH 6 (sections 6.1 and 6.3 only) will be this Friday, 03/10/17)
1. Notes: relative velocity in 2-D
Goal: Students will build on the knowledge gained from the relative velocity videos and practice problems in Day 59
Review pg 158 Example Problem 3
2. Practice Problems:
pg 166: 68, 69, 70, pg 167: 75
3. Difficult Practice Problems :-/
pg 167: 72, 73
HOMEWORK
Next class we will begin studying momentum and collisions
Add the symbol, equation, and units for momentum to your equation chart, which I'll check for HW. Add the equation for Force of Impact to your chart as well.
#Goals: SWBAT...
1. Calculate Impulse
2. Define the angular momentum of an object
3. Measure in SI the momenta involved
4. Interpret Data from a collision.
5. Draw Conclusions that support the law of conservation of momentum.
WARM-UP & HW Check:
A. What is the formula for momentum? (don't forget vector symbols)
B. What's the formula for impulse?
C. https://www.youtube.com/watch?v=fdeH6Ksedwk
Impulse is the change in momentum (Δp).
1. Is the impulse when the brick hits the table the same or different as the brick hitting the foam?
When our video presenter jumps from the table, he begins falling.
2. Does his momentum increase, remain constant, or decrease?
3. Does he want to experience a strong force when he lands? Why/why not?
4. How does he protect himself upon landing?
5. Why are running shoes helpful for our feet?
CLASSWORK:
1. Practice Problems
pg 233 #3 & 4
2. Momentum Notes:
Copy the definition for momentum into your notes:
- the force or energy with which a body moves, measured as a product of its mass and velocity.
Linear Momentum is expressed as p=mv
Angular Momentum is expressed L=Iω
ADD THE NEXT 4 LINES TO YOUR TABLE OF FRIENDS
Formula: L=Iω
Def: the force or energy with which a body rotates, measured as a product of its moment of inertia & angular velocity.
Units: kg-m2/s
Symbol: L
If there are no forces acting on an object, its linear momentum is constant.
Similarly, if there are no torques acting on an object, its angular momentum is constant.
Can an object's mass change?
Because an object's mass cannot be changed, if the momentum is constant, velocity must also be constant.
What does this all mean? Take a look at pg 234 figure 9-4
3. Momentum Lab
http://www.glencoe.com/sec/science/internet_lab/olc.php?olcChapter=809
Your Final Product:
- Word Document with:
A. Answers to each question from: Analyze, Conclude & Apply; Going Further; Real-World Physics secitions
B. Completed data table.
- fill this out on the webpage. Then use ctrl-printscreen to take a screen shot, and ctrl-v to paste the
tables on your Word document.
Tutoring available after school Mon, Tues, and Wed until 4:30. Lunch almost every day.
HOMEWORK:
1. Complete #5 from pg 233; and #9-11 on pg 235
2. Complete lab