Is a force necessary to keep an object in motion?

Well according to Newton’s first law of motion, a body will remain in the state of rest or linear motion provided that an *external force* has been applied. So no, a force doesn’t need to keep a body to remain in linear motion, because F=ma, during uniform linear motion velocity is constant, hence acceleration is zero, so F=0

h = 44.5 m

Explanation:

Given that,

Power of the engine, P = 5 hP = 3728.5 W

Weight of the load, W = 2000 lb = 8900  kg

We need to find how high the load be raised in 10 s.

We know that,

Power,

Where

W is work done

Also,

1 Pound = 4.45 newtons earth (N)

So, the height raised by the load is 44.5 m.