Question

What must be happening, according to Newton's second law of motion, if a rigid body of unchanging mass is observed accelerating?

A force is being applied to the mass.


A force was once applied but is now not being applied.


The mass must be changing.


No force was or is being applied to the mass.

Answer 1

A force being applied to the mass is the correct answer

Step-by-step explanation:

Answer 2

A force is being applied to the mass.