Impulse & Momentum
If a force of 100 N acts on an object for 1 s, and another force of 100 N acts on a second object for 2 s, which object gains more momentum?
The Second Object
How long should a 130 N force act on a 50 kg object to change its speed from 20 m/s to 60 m/s?
15.4 seconds
What is the kinetic energy of a 0.01 kg bullet traveling at 700 m/s?
2450 Joules
Can a lighter object have more momentum than a heavier one?
Yes, if its velocity is higher than the heavier object.
How much force is needed to create a momentum change of 17 kg⋅m/s over 5 seconds?
3.4 Newtons
What is the recoil velocity of a 70 kg man throwing a 5 kg object at 50 m/s on a frictionless surface?
-3.6 m/s
When a marble rolls up a ramp without friction at 2 m/s, what height does it reach?
.20 meters
An object with momentum 25 kg⋅m/s collides with another with 35 kg⋅m/s. If the first changes to 15 kg⋅m/s, what is the second's momentum after?
45 kg⋅m/s
In a collision (with no external forces) where two cars come to rest, what can be said about their initial and final momenta?
Their initial momenta must have been equal in magnitude and opposite in direction.
A boy pushes a sled that accelerates from 0 to 3.2 m/s. If the sled's mass is 40 kg and 18 W of power were used, how long did he push?
11.4 seconds
If a car's engine generates 100,000 W of power and exerts a force of 10,000 N, how long to travel 100 m?
10 Seconds
In an elastic collision, what is true about momentum?
Total momentum is conserved.
If two people throw objects of different masses at the same speed, who experiences greater recoil?
The one who threw the object with a greater mass
If a baseball player exerts 100 N on a 0.15 kg ball for 0.5 m, what is its exit velocity?
25.8 m/s
How is the energy of a person jumping on a trampoline described in terms of KE and PE?
On the way up, KE becomes PE. On the way down, PE become KE.
If two objects collide and come to rest, how is momentum conserved?
As long as the objects have equal but opposite momentums before the collisions, their total momentum should still be zero.
If the momentum of an object changes from 50 kg⋅m/s to 15 kg⋅m/s, what happens to the other object involved in the collision?
The other object must have gained 35 units of momentum.
What force is needed to create a change of 35 kg⋅m/s over 5 seconds?
7 Newtons
Why does it hurt less to fall on a soft surface?
The soft surface increases the time you have to fall, which in turn decreases the force.
How does a heavier object affect collision outcomes?
An heavier object applies a greater force and increases the change in velocity of the lighter object.