Question

According to Newton's second law of motion, if we have a rigid, unchanging mass and we observe it accelerating, what must be happening?

A.
a force is being applied to the mass

B.
a force was once applied but is now not being applied

C.
no force was or is being applied to the mass

D.
the mass MUST be changing

Answer 1

i think its either A or B

Answer 2

I believe you're right, it's going to be A! A mass cannot move without a force being applied to it. If it stopped being applied, the object would stop moving (if we're factoring in air resistance and friction that is. Otherwise, the force of inertia would keep it moving).

Answer 3

@gaberdeen thanks! :)