Question

which of the following is an example of acceleration without speeding up?

• 5 points

a) a car parked in a driveway.
b) a car driving at a constant speed in a straight line.
c) a car slowing down to stop at a red light.
d) a car turning a corner at a constant speed.

Explanation:

To determine acceleration, we check for changes in velocity (speed or direction).

• Option a: A parked car has velocity \( 0 \), no change, but it's not moving.
• Option b: A car moving at constant speed in a straight line has no change in speed or direction, so velocity is constant, meaning acceleration is \( 0 \) (no acceleration).
• Option c: Slowing down means speed is decreasing (change in velocity), so there is acceleration (deceleration).
• Option d: Turning a corner means direction changes (change in velocity), so there is acceleration.

So the only case without acceleration (or speeding up/slowing down/change in direction) is option b.

Answer:

b. A car driving at a constant speed in a straight line.