Answer:(a)10 ft/s
(b)4 ft/s
Explanation:
Given
height of light 
height of man

From diagram



differentiate both sides

Tip of shadow is moving at the rate of

(b)rate at which length of his shadow is changing
Length of shadow is 
differentiating w.r.t time


Answer: C and D
The equipment would have stayed in the same exact location indefinitely until the very moment the astronaut applied force to it.
The equipment will continue moving in the same direction indefinitely unless another force is applied to stop it.
Explanation: According to Newton's first law of motion which state that; A body at rest will continue to be at rest, or in linear motion will continue to move in a straight line, unless an external force act on it.
The equipment would have stayed in the same exact location indefinitely until the very moment the astronaut applied force to it.
immediately the astronaut apply force to the object by pushing in, Newton's first law will be manifested in which the equipment will continue moving in the same direction indefinitely unless another force is applied to stop it.