Question

A car is driving 55 miles per hour east. The car changes direction to head north but still travels at 55 miles per hour. Which is true?
The car is following Newton's third law of motion.
The car is not accelerating.
The car is accelerating.

Answer 1

Answer:

Just as distance and displacement have distinctly different meanings (despite their similarities), so do speed and velocity. Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. Contrast this to a slow-moving object that has a low speed; it covers a relatively small amount of distance in the same amount of time. An object with no movement at all has a zero speed.

Answer 2

The car is accelerating (during the short time that it's turning from East to North).

ANY change in speed or direction of motion is acceleration.  Since the car is changing direction, it is accelerating, even though its speed is constant.