15. an insect lands on a compact disc that is put
into a player. if the insect spins with the disc,
is the insect accelerating? why or why not.

Yes, it is accelerating

Explanation:

Acceleration is a vector quantity, which means it has both a magnitude and a direction.

Acceleration is defined as the rate of change of velocity:

where v is the velocity and t is the time.

v, the velocity, is also a vector, having both a magnitude (called speed) and a direction. This means that the acceleration is non-zero whenever the velocity is  changing: this means that we have an acceleration either when the speed is changing, or also when the direction of the velocity is changing.

In the example in the question, the insect spins with the disc, so it is in circular motion. This means that the direction of the velocity of the insect is constantly changing: therefore, the acceleration of the insect is non-zero, so the insect is accelerating.