A 88.9 kg astronaut is working on the en-

gines of a spaceship that is drifting through

space with a constant velocity. The astronaut

turns away to look at Earth and several sec-

onds later is 30.7 m behind the ship, at rest

relative to the spaceship. The only way to re-

turn to the ship without a thruster is to throw

a wrench directly away from the ship. The

wrench has a mass of 0.502 kg, and the astro-

naut throws the wrench with a speed of 24.3

m/s.

How long does it take the astronaut to reach

the ship?

Answer in units of s.

A(n) 2.96 kg sphere makes a perfectly in-

elastic collision with a second sphere that is

initially at rest. The composite system moves

with a speed equal to one-third the original

speed of the 2.96 kg sphere.

What is the mass of the second sphere?

Answer in units of kg.