Motion and Velocity Quiz

Speed and Distance

• The SI unit for length or distance is meter (m).
• Speed is the rate at which distance is covered.

Acceleration

• Acceleration is the rate at which velocity changes.
• To determine which car has the greatest acceleration, calculate the rate of change in velocity.

Velocity

• Velocity is the rate of change in displacement with respect to time.
• Formula to calculate speed: speed = distance / time.
• A tiger travels 96 m in 8s, so its velocity is 96 m / 8 s = 12 m/s.
• A cheetah travels 75 m in 3 s, so its velocity is 75 m / 3 s = 25 m/s.

Distance-Time Graphs

• A horizontal line on a distance-time graph indicates that the object is stationary.
• The distance-time graph shows the journey of a student who walks 2.0 km in 30 minutes, stops for 15 minutes, and then travels 1.0 km in 15 minutes.

Motion

• Velocity has both magnitude and direction.
• The rate at which velocity changes is called acceleration.
• An object moving at a constant speed away from the start and then stopping is represented by a horizontal line on a distance-time graph.

Examples

• Edward drove 80 miles from his home to London, stopping to visit his friend Nicola on the way. He was 40 miles from home when he visited Nicola.
• An object travels 400 m in 20 minutes, so its speed is 400 m / 20 min = 20 m/min.
• A lizard runs 8 m across the water in 4 seconds, so its speed is 8 m / 4 s = 2 m/s.