A
Two carts collide; in the center-of-mass frame, this quantity reverses for each cart.
What is velocity?
In this type of collision, momentum is conserved but kinetic energy is not.
What is an inelastic collision?
This principle explains how a rocket accelerates even in empty space.
What is conservation of momentum?
This collision maximizes kinetic energy loss while still conserving momentum.
What is a perfectly inelastic collision?
This time integral of force equals the change in momentum, even when the force is not constant.
What is impulse?
A 3.50g bullet is fired horizontally at two blocks at rest on a frictionless table. The bullet passes through block 1 (mass 1.20kg) and embeds itself in block 2 (mass 1.80kg). The block ends up with velocities v1,f = 0.63m/s and v2,f = 1.40m/s. Assume that no material is removed from block 1 by the bullet. Find the speed of the bullet as it enters block 1.
937^ı m/s.
You have an inertia of 52kg and are standing at rest on an iced-over pond in your skates. Suddenly, your 60kg brother skates in behind you at a speed of 5.0m/s and collides elastically with you. Use a reference axis x where the positive direction corresponds to the direction you are facing in. If your brother's final x component of velocity is +0.36m/s, calculate your final velocity.
5.4 m/s
A 52kg ice skater (whose weight includes two 1.0kg snowballs she is carrying) is at rest on the ice. She throws a snowball forward (in the direction she is facing, which corresponds with the positive x direction) at 10m/s. Calculate her velocity after the throw.
0.20 m/s.
A 52kg ice skater (whose weight includes two 1.0kg snowballs she is carrying) is at rest on the ice. She throws her second snowball at a speed of 20m/s backwards. Calculate the change in kinetic energy in this event and comment on the source of additional kinetic energy.
2.0 × 10^2 J, from food
A 52kg ice skater (whose weight includes two 1.0kg snowballs she is carrying) is at rest on the ice. She throws her second snowball at a speed of 20m/s backwards. Calculate the coefficient of restitution for this event.
(Hint: e = final relative speed/initial relative speed)
→∞. This is common for explosions and comes from initial relative speed=0.