Question

scribing motion from a circular motion map
an object is represented by the dot on a motion map. what is the best description for the motion of this object?
the object is moving with a constant speed.
the object is moving with a constant acceleration.
the object is standing still.
the object is falling.

Explanation:

• If an object is moving in a circular motion map (assuming a standard circular motion map where the spacing between positions in the circular path is uniform), uniform spacing implies constant - speed.
• For constant acceleration in circular motion, the acceleration is centripetal (\(a = \frac{v^{2}}{r}\)), but the direction of acceleration is always changing (towards the center of the circle), so it is not a constant - acceleration in the sense of having a constant vector (magnitude and direction).
• If the object were standing still, it would not be on a circular path (it would be a single, stationary dot).
• If the object were falling, its motion map would likely show a linear (downward) path rather than a circular path.

Answer:

The object is moving with a constant speed.