Momentum
What is the formula for momentum?
p=mv
What is the formula for impulse?
J=F (change in) t
What is the difference between the 3 types of collisions?
Momentum and KE conserved-elastic. Momentum but not KE conserved-inelastic. Perfectly inelastic-max KE is lost, objects stick together.
What is the formula for change in momentum?
p=m(change in) v
Describe the relationship between momentum and impulse
change in momentum equals impulse
A 70-kg student stands at rest on frictionless ice holding a 5-kg bowling ball. They throw the ball forward at 8 m/s.
What is the student’s recoil velocity?
- 0.57 m/s
A cart with a large mass and a cart with a small mass roll at the same speed. Which cart has more momentum?
Large mass
Which has the greatest impulse? A large force over a short time or a large force over a long time?
A large force over a long time
A 0.50-kg cart moving at 3.0 m/s collides elastically with a 1.00-kg cart initially at rest. The 0.50 kg cart moves with a final velocity of 1.0 m/s. What is the final velocity of the 1.00 kg cart?
1.0 m/s
A 2 kg toy car is moving 2.5 m/s. What is the momentum?
5 kgm/s
Why is the risk of injury less when a car crashes into a crash cushion?
Extends the time of the collision so the force is less.
A 1200-kg car is traveling east at 22 m/s when it rear-ends a 900-kg car moving east at 15 m/s. The cars lock together after impact.
What is their combined velocity immediately after the collision?
19 m/s
A .25 kg dart initially moving 5 m/s hits a dart board and bounces off at 2 m/s. What is the change in momentum?
-1.75 kgm/s
A kid sledding down a hill hits a snow pile with 10 N of force in .032 seconds. What is the impulse?
0.32 Ns
What is the final kinetic energy of the system if 2 pizza doughs, each of mass .5 kg, collide and have a resultant velocity of 1.5 m/s?
1.125 J