If a force does a positive amount of work on an object, does the object's speed increase, decrease, or remain the same? Justify your answer.

see that there is no dependence on speed, so the work remains constant

Explanation:

Work is defined by the expression

W = F. d

where the boldface indicates vectors, this equation can be written in scalar form

W = f d cos θ

where θ is the angle between force and displacement.

We see that there is no dependence on speed, so the work remains constant

The power is

P = W / t

P = f d / t

p = F v

we see that the power is the one that depends on the speed of the body