Question

Nate the Skate was an avid physics student whose main non-physics interest in life was high-speed skateboarding. In particular,
Nate would often don a protective suit of Bounce-Tex, which he invented, and after working up a high speed on his skateboard,
would collide with some object. In this way, he got a gut feel for the physical properties of collisions and succeeded in
combining his two passions.* On one occasion, the Skate, with a mass of 117 kg, including his armor, hurled himself against a
879 kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.63 m/s and
Nate bounced backward.
What were Nate's speeds immediately before and after the collision? (Enter positive numbers). Ignore friction with the ground.

Answer 1

Answer:

Explanation:

The statue, being initially at rest, will move off at twice the velocity of the center of mass of the Skate-Statue system

The CM velocity is 1.63/2 = 0.815 m/s

so the Skates initial velocity can be found

(117 + 879)(0.815) = 879(0) + 117u

u = 6.93794...

|u| = 6.94 m/s

for elastic collisions, the relative velocity of approach will equal the relative velocity of departure.

Approach velocity 6.94 m/s

Skate's departure velocity 1.63 - 6.94 = - 5.31 m/s

|v| = 5.31 m/s