IPS - Sports: Chapter 2 - Problems
Momentum
1. What is the equation for the momentum of an object?
2. Fill in the memory circle at the right with the momentum equation.
3. What are the units for momentum?
4.A 50.0-kg (110-pound) football player is running at 3 m/s. What is his momentum.
5.A 5.0-kg object is moving at 30 m/s, what is its momentum?
6.An object with a momentum of 120 kg.m/s has a velocity (speed) of 15 m/s. What is the mass of the object?
7. An object with a mass of 3.2 kg has a momentum of 54 kg.m/s. What is the velocity of the object.
8.A 1,000-kg car (compact car) has a velocity of 14 m/s (about 30 mph). What is the momentum of the car?
9.How fast would a 3,500-kg truck (pickup truck) have to travel in order to have the same momentum as the car in #5?
10.A boy in a wagon has a total mass of 60 kg (about 132 pounds). How fast would the wagon have to be moving to have the same momentum as the car in #5? Is this practical, the speed of sound in about 320 m/s?
11. What is meant by "Conservation of Momentum" (starts on p.92) ?
12. Tom’s mom, mass is 75 kg, is skating to the right at 5.0 m/s. What is her momentum?
13. Tom, has a mass of 25 kg and is at rest on the ice. What is Tom's momentum?
14. Mom sneaks up behind Tom, grabs him and picks him up so that they skate off together. What is the speed on Mom and Tom after she picks him up? Let's do this in steps.
a. The sum of the initial momenta of Mom and Tom =
(Before Mom picks up Tom. You have the data above.)
b. The total final momentum of Mom and Tom together =
(After Mom picks up Tom. Use Cons. of momentum.)
c. The total mass of Mom and Tom together =
d. What is the final velocity of Mom and Tom together?
9.Mom, mass is 75 kg, is skating to the right at 5.0 m/s. What is her momentum?
Mom sneaks up behind Tom with the intention of picking him up so that they skate off together, but this time Tom sees Mom coming and tries to skate away from her. He is moving at 2.0 m/s when Mom catches up to him and picks him up so that they skate off together. What is the speed on Mom and Tom after she picks him up? Let's do this in steps.
Calculate the initial momentum of Tom (before Mom catches up to him.)
The sum of the initial momenta of Mom and Tom =
(Before Mom picks up Tom. You have the data above.)
The total final momentum of Mom and Tom together =
(After Mom picks up Tom. Conservation of momentum.)
What is the final velocity of Mom and Tom together?
10.Mom, mass is 75 kg, is skating to the right at 5.0 m/s. Mom skates towards Tom with the intention of picking him up so that they skate off together, but this time Tom sees Mom coming and skates towards her at 2.0 m/s. Mom catches up to him and picks him up so that they skate off together. What is the speed on Mom and Tom after she picks him up?
Calculate the initial momentum of Mom.
Calculate the initial momentum of Tom.
What is the sum of Mom and Tom's initial momenta? Does it make a difference that they are skating towards each other? So, direction is important when we work with momentum.
The total final momentum of Mom and Tom together =
What is the final velocity of Mom and Tom together?
11.Now back to the football players. A 100-kg fullback is running at 5.5 m/s towards an 80-kg cornerback. They have a head-on collision and the cornerback tackles and hangs on to the fullback. If the cornerback stops the fullback, what was the initial velocity of the cornerback?
Think about this for a moment. If, as a result of the collision, the fullback is stopped in his tracks, what is the final momentum of the system (two football players)?
What must be the initial momentum of the system of the fullback and cornerback before collision?
What is the initial momentum of the fullback (before collision and tackle)?
What must be the initial momentum of the cornerback in order to stop the fullback?
What is the initial velocity of the cornerback?
Sports: Chapter 2 - Momentum Problemspage 1 10/25/2018