Can object have a varying speed if its velocity is constant? Can it have varying velocity if its speed is constant? If yes, give examples in each case.

1 Answer
Mar 3, 2018

First question: No
Second question: Yes

Explanation:

Speed is a scalar quantity
Velocity is a vector quantity
Velocity therefore has two parts to it, the magnitude which is the speed, and the direction for that motion.

Here's your example:
You are going on a highway at a constant velocity 100 mi/hr east, and since the velocity already includes speed as a magnitude, the speed is also constant but has no direction.

Second one example: You are going around a circular track at a constant speed of 10 mi/hr. Since, it's a circular track, will the direction of your travel be the same? Therefore, in this case the magnitude of velocity which is speed is constant, but the velocity changes due to the change in direction.