DAY 73
GOALS: SWBAT....
1. Solve impulse and force problems
2. Solve 2-dimensional conservation of momentum problems
3. Prep for Friday's CH 9 exam
WARM-UP
Solve the following problem by:
A/ writing the given info B/ drawing a coordinate system C/sketching the scenario
D/ solving the problem using GUESS
Problem 1. A ball with an initial momentum of 6.00 kg m/s bounces off a wall and travels in the opposite direction with a momentum of 4.00kg m/s. What is the magnitude of the impulse acting on the ball?
Problem 2. If the ball in the previous problem interacts with the wall for a time interval of 0.22s, what is the force exerted on the wall?
CLASSWORK
1. Quiz Make-up & Return
2. Review of Impulse and Momentum
Watch the following video, and answer the questions listed below
A. in the conservation of momentum equation, what is signified by the small 1's and 2's
B. what about the little i and f?
C. In the conservation of momentum equation, why must there be at least
two mv terms on each side of the equals sign?
D. What is F Δt equal to?
Video LINK
3. Practice Problems
A. An ice skater with a mass of 75.0kg pushes off against a second skater with a mass of 42.0kg. Both skaters are initially at rest. After the push, the larger skater moves off with a speed of 0.75m/s eastward. What is the velocity (magnitude and direction) of the smaller skater after the push?
B. A 42.0kg skater traveling at 1.50m/s hits a wall and bounces off of it. If the magnitude of the impulse is 150 kg*m/s, calculate the final velocity of the skater.
4. Review of 2-D problem solving
We will review the 2-d problem from the DAY 72 extra credit
A 975g car "C" moving south at 22.5m/s, collides with a 2156kg truck "D", moving west at 17.5m/s. They stick together. In what direction and with what speed do they move after the collision?
5. Practice with 2-D
A. An 82kg receiver, moving 0.75m/s north
6. CH 9 Exam is Friday
Flipping Physics review videos are here in the Momentum & Impulse section:
http://www.flippingphysics.com/algebra.html
Practice Problems: You should know how to solve each of these: pg 250-255: 47, 59, 65, 70, as well as problems 33, 34, 36, 38, 39, 40, 42 and the problem written out below:
A. A 975g car "C" moving south at 22.5m/s, collides with a 2156kg truck "D", moving west at 17.5m/s. They stick together. In what direction and with what speed do they move after the collision?
We will review some of these problems in class Wednesday.
Thursday and Friday I won't be here, so if you have questions, you'll need to ask Wednesday, or via Remind/email.
HOMEWORK
Bring your notes sheet for the CH9 exam this Friday.
Bring a calculator (no phones allowed)
Bring your equation sheet
Work on practice problems listed above (aka, study)
#Goals: SWBAT...
1. ... review the components of "Power"
2. ... solve advanced work and power problems
3. ... create and share graphs showing power output of a person climbing stairs
WARM-UP:
Still R.I.P Prince
1. Complete the following:
Power is the work done, divided by the _____ taken to do the work. In other words, power is the _____ at which the external force changes the energy of the system. It is represented by the following equation. P=___ / ___
2. An electric motor lifts a forklift 10.00 m in 15.0 s by exerting an upward force of 1.20x104 N.
What power does the motor produce in kW? (hint: look up the conversion factor for kW to w)
A. Sketch the situation showing the forklift with initial conditions.
B. Establish a coordinate system with up as positive.
C. Draw a vector diagram for the force and displacement.
D. Solve for Power
CLASSWORK:
1. Practice Problems.
Solve pg 264 9-14 for classwork credit.
Your group will need to present one problem on the board
9: Itzel 9: Alexa
10: Ricky 10. Karina
11: David 11. Andrea & Vanessa
12: Brandon 12. Ariella
13: Shelia 13. Parker
14: Koraima 14. Mr. President
2. Power Lab Analysis
TASKS:
Calculate and Fill-in a Typed Data Table
Divide the "Conclude", "Apply/Going Further", and "Real World Physics" questions so each member has a fair amount.
End of day check:
- Have you shared or emailed the data table and graphs to all group members?
3. Lab Requirements:
Typed.
Introduction (answer the main question by presenting your hypothesis)
Data (data table and graphs go here)
Analysis Section
- will be completed in parts. Each group member will answer one to four questions. Those will be turned in on the due date (Friday 04/29), and will be the sole responsibility of the group member to which they are assigned.
Conclusion (was your hypothesis correct?)
HOMEWORK:
1.pg 265: 15-18