Question

which of the following are examples of acceleration?

a car travels at a constant speed and turns left.
a car travels in a straight line at a constant speed.
a car slows down.
a car speeds up.

Explanation:

Define acceleration

Using the Kinematics Definitions and Velocity Change knowledge points

$$ \vec{a} = \frac{d\vec{v}}{dt} $$

Velocity is a vector quantity with both magnitude (speed) and direction. Acceleration occurs if speed changes, direction changes, or both change.

Analyze each scenario

Using the Speed vs Acceleration knowledge point

• A car travels at a constant speed and turns left: Direction changes, so velocity changes. This is acceleration.
• A car travels in a straight line at a constant speed: Neither speed nor direction changes. No acceleration.
• A car slows down: Speed changes. This is acceleration.
• A car speeds up: Speed changes. This is acceleration.

Answer:

• A car travels at a constant speed and turns left. (Correct answer)
• A car travels in a straight line at a constant speed.
• A car slows down. (Correct answer)
• A car speeds up. (Correct answer)