Question

multiple cholce question
a stone is attached to the end of a string and moved in a circular horizontal path. as the stone moves, it maintains a constant speed. which statement correctly
describes the stones acceleration?
o the stone only reacts to acceleration due to gravity.
o because the stone is at a constant speed, there is no acceleration.
o the stone only experiences acceleration due to gravity.
o there is acceleration because the direction is changing.

Explanation:

Step1: Recall the definition of acceleration

Acceleration is a vector quantity. It is defined as the rate of change of velocity. Velocity is also a vector quantity which has both magnitude (speed) and direction.

Step2: Analyze the motion of the stone

The stone is moving in a circular horizontal path with a constant speed. But its direction is constantly changing as it moves along the circular path. Since velocity (due to direction change) is changing, there is an acceleration. This acceleration is called centripetal acceleration. It is not related to gravitational acceleration in this context (as the motion is horizontal and the problem is about the nature of acceleration due to circular motion, not vertical fall - like gravitational acceleration effects). Just having a constant speed (magnitude of velocity) is not enough to say there is no acceleration because direction is part of velocity.

Answer:

There is acceleration because the direction is changing.