Question

An object in motion stays in motion, in a _______________________, unless acted on by an external _____________________________ force.

Answer 1

Answer:

See the explanation below.

Explanation:

in a motion (or constant speed) unless acted on by an external  unbalanced force.

This explanation corresponds to newton's second law which tells us that the sum of the forces acting on a body is equal to the product of mass by acceleration, if the object moves with constant speed it is because on this act forces that do not decrease to increase its speed.