Energy...etc?

Question

1) A 2.0kg trolley moving east at 3.0m/s collides head-on with a 1.0kg trolley moving west at 2.0m/s. After the collision, the 2.0kg trolley has a velocity of 1.0m/s[E].

(a) What is the final velocity of the 1.0kg trolley?

(b) Is the collision elastic or inelastic? Show calculations.

2) A rifle bullet of mass 10.0g strikes and becomes embedded in a wooden block of mass 490g, which is at rest on a horizontal, frictionless surface and is attached to a spring bumper. The impact compresses the spring, whose force constant is 100N/m, by 20cm.

(a) What is the maximum potential energy of the spring?

(b) Determine the velocity with which the block and the bullet first begin to move.

(c) What was the initial velocity of the bullet?

(d) What was the initial kinetic energy of the bullet?

(e) Explain any difference between (a) and (d)

Answer 1

an advice to solve any problem in collision: write down two equateions of conservation of energy and momentum

then you would be able to find any unknown quantities.

for second problem you equat the potential of spring (1/2 kx^2) to the kinetic (1/2 mv^2) and find the speed immediately after reach