Momentum
A truck is moving eastward and slowing down. The direction of the truck's momentum vector is ______.
a. east
b. west
c. impossible to tell
a. east
A box starts with 5 kgm/s of momentum and ends with 20 kgm/s of momentum. What is the change in momentum of the box?
15 kgm/s
Case A: A 600-mL water balloon moving at 8 m/s is caught and brought to a stop.
Case B: A 150-mL water balloon moving at 8 m/s is caught with the same technique and brought to a stop.
The collision time is the same for each case.
Which variable is different for these two cases?
a. Mass
b. Delta V
c. Time
Mass
An object experiences a 25 N force for 2 seconds. What is the impulse it experiences?
50 Ns
Alek extralegally drives a 1000 kg car at a speed of 10 m/s and sees Levi down the street. He speeds up to 25 m/s in order to give Levi a boost to his destination. What is the impulse Alek experiences as he speeds up?
15000 kgm/s
A car is moving eastward and speeding up. The momentum of the car is ______.
a. increasing
b. decreasing
c. remaining constant
a. increasing
A box starts with 9 kgm/s of momentum and ends with 27 kgm/s of momentum. Which of the following combinations represents the change in momentum of the box?
a. F = +3 N, ∆t = 9 s
b. F = +9 N, ∆t = 2 s
c. F = +12 N, ∆t = 3 s
d. F = +18 N, ∆t = 6 s
e. F = +36 N, ∆t = 3 s
b. F = +9 N, ∆t = 2 s
Case A: A "sad ball" collides the floor moving at 2 m/s and stops.
Case B: A "happy ball" with the same mass collides with the floor moving at 2 m/s and rebounds upward at 1 m/s.
The collision time is the same for each case.
Answer BOTH questions:
Which variable is different for these two cases (Mass, Delta V, or Time)?
Which case involves the greatest momentum change?
Delta V, Case B
An object experiences 8 Ns of impulse over 2 seconds. What is the force it experiences?
4 N
Elena crashes out because Gabby won't help her with a problem, and she runs into the hallway with a speed of 6 m/s. She sees a monitor standing right outside and quickly comes to a stop. If Elena's mass is 30 kg, how much impulse does she experience as she slows down?
-180 kgm/s
A truck is moving southward at a constant speed. The momentum of the car is ______.
a. increasing
b. decreasing
c. remaining constant
c. remaining constant
A 4kg box speeds up from 5 m/s to 12 m/s. What is the impulse the box experiences?
a. 7 kgm/s
b. 14 kgm/s
c. 17 kgm/s
d. 28 kgm/s
e. 96 kgm/s
d. 28 kgm/s
Case A: A 75-kg PE student moving at 8 m/s collides with an unpadded wall and stops.
Case B: The same 75-kg PE student moving at 8 m/s collides with a padded wall and stops.
Answer ALL the following questions:
Which variable is different for these two cases?
Which case involves the greatest momentum change?
Which case involves the greatest impulse?
Time, Same, Same
An object initially moving with a momentum of 31 kgm/s experiences 9 Ns of impulse. What is the change in momentum of the object?
9 kgm/s
Upon finding out that they're allowed to work outside in the pod, Maya shoves Olivia (35 kg) out of the classroom for 3 seconds, speeding her up from 2 m/s to 8 m/s. How much force did she apply?
70 N
Rank the following objects in order of greatest to least momentum:
A - 2 kg object moving 6 m/s
B - 2 kg object moving 7 m/s
C - 16 kg object moving 0 m/s
BAC
A 3kg box speeds up from 6 m/s to 14 m/s. Which of the following combinations represents the change in momentum of the box?
a. F = +2 N, ∆t = 3 s
b. F = +4 N, ∆t = 3 s
c. F = +8 N, ∆t = 3 s
d. F = +20 N, ∆t = 3 s
e. F = +24 N, ∆t = 3 s
c. F = +8 N, ∆t = 3 s
Case A: A 1200-kg car moving at 18 m/s collides with a barrier and crumples up as it stops.
Case B: The same 1200-kg car moving at 18 m/s collides with a barrier and bounces backward with a speed of 6 m/s.
Answer ALL the following questions:
Which variable is different for these two cases?
Which case involves the greatest momentum change?
Which case involves the greatest impulse?
Which case involves the greatest force?
Delta V, B, B, B
An object initially moving with a momentum of 15 kgm/s experiences 7 Ns of impulse. What is the final momentum of the object?
22 kgm/s
Joey loses a game of Clash and throws his 1.5 kg phone against the wall with a speed of 5 m/s. What is the force his phone experiences if it stops over 0.01 seconds?
750 N (-750 N also acceptable)
Rank the following objects in order of greatest to least momentum:
A - 4 kg object moving 5 m/s
B - 3 kg object moving 6 m/s
C - 6 kg object moving 4 m/s
CAB
A 2kg basketball moving at 5 m/s hits a wall and bounces back with a speed of -4 m/s. What is the impulse the basketball experiences?
a. -54 kgm/s
b. -18 kgm/s
c. 1 kgm/s
d. 18 kgm/s
e. 54 kgm/s
b. -18 kgm/s
Case A: A 50-kg car driver moving at 12 m/s is stopped by a dashboard during a front-end collision.
Case B: The same 50-kg car driver moving at 12 m/s is stopped by an air bag during a front-end collision.
Answer ALL the following questions:
Which variable is different for these two cases?
Which case involves the greatest momentum change?
Which case involves the greatest impulse?
Which case involves the greatest force?
Time, Same, Same, A
An object experiences -18 Ns of impulse and slows down to a momentum of 16 kgm/s. What was the initial momentum of the object?
34 kgm/s
Mr. Faezi throws a happy ball and a sad ball at a student who isn’t paying attention in class. Both balls have a mass of 0.2 kg, and he throws them both with an initial velocity of 6 m/s. The happy ball bounces off of the student with a velocity of -2 m/s, while the sad ball stops moving after hitting the student. If both collisions took place over 0.15 s, calculate the force exerted by each ball during the collisions. Which ball experiences more force?
Happy Ball: 10.67 N
Sad Ball: 8 N
Happy Ball!