Which of these does not result in the acceleration of an object?
a.) a decrease in speed
b.) an increase in speed
c.) a change in direction
d.) maintaining a constant velocity

I guess the correct answer is the first one.

The correct answer is D.

Acceleration is defined as a change in velocity. A and B clearly demonstrate a change in velocity so are eliminated. And since velocity is a vector quantity that consists of both magnitude and direction, C is also eliminated because it has a change in direction.

Let me know if you have any questions.

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm