When motion IS changing directions, acceleration is the rate at which ________changes, but when motion is NOT changing direction, acceleration may be expressed as the rate at which ________ changes.

A. speed, time
B. velocity, speed
C. elapsed time, average speed

Question

When motion IS changing directions, acceleration is the rate at which ________changes, but when motion is NOT changing direction, acceleration may be expressed as the rate at which ________ changes.

A.	speed, time
	B.	velocity, speed
	C.	elapsed time, average speed

hunus · Answer

B. Velocity is a vector with direction an magnitude, thus if you change either of those quantities there is acceleration. Speed is a scalar quantity and isn't associated with a direction, thus if you change the speed you aren't necessarily changing the direction.