Question

A puck traveling at 6 m/s in the +x direction hits a wall and bounces back. Right after the collision with the wall it is traveling in the −x direction at 6 m/s. What type of collision occurred ? (Assume the wall does not move) Inelastic Elastic There is not enough information provided to determine

Answer 1

Answer:

Elastic collision

Explanation:

An elastic collision is one in which the net kinetic energy of the bodies involved is conserved i.e. remains the same.

Calculating the total initial kinetic energy of the system of the puck, with mass m and Wall with mass M:

KEini = ½m(u1)² + ½M(u2)²

Where u1 is the initial speed of the puck, 6 m/s

u2 is the initial speed of the wall, 0 m/s

Hence, the total initial KE is:

KEini = ½m(6)² + 0 = 18m

Calculating the total final kinetic energy of the system of the puck and wall:

KEini = ½m(v1)² + ½M(v2)²

Where v1 is the final speed of the puck, 6 m/s

v2 is the final speed of the wall, 0 m/s

Hence, the total final KE is:

KEini = ½m(6)² + 0 = 18m

Since the KE is conserved, the collision is elastic.