Unit 1 - Movement and Position

What is speed defined as?

• Velocity multiplied by time

• Time divided by distance

• Distance divided by acceleration

• Distance travelled per unit time

Answer explanation

Speed is defined as the distance travelled per unit time, which measures how fast an object moves. This is correctly represented by the choice 'Distance travelled per unit time', making it the right answer.

What does a negative gradient in a displacement-time graph indicate?

• Object is moving at constant speed

• Object is accelerating

• Object is returning to the starting point

• Object is stationary

Answer explanation

A negative gradient in a displacement-time graph indicates that the displacement is decreasing, meaning the object is moving back towards its starting point. Thus, it shows the object is returning to the starting point.

What is the unit of acceleration?

• Metres (m)

• Seconds (s)

• Metres per second squared (m/s²)

• Metres per second (m/s)

Answer explanation

Acceleration is defined as the rate of change of velocity per unit time. Its unit is derived from velocity (m/s) divided by time (s), resulting in metres per second squared (m/s²), which is the correct answer.

What does acceleration measure?

• Change in time per unit distance

• Change in speed per unit distance

• Change in velocity per unit time

• Change in distance per unit time

Answer explanation

Acceleration measures the change in velocity per unit time, indicating how quickly an object's speed or direction is changing. This makes 'Change in velocity per unit time' the correct choice.

In a velocity-time graph, what does the area under the line represent?

• Displacement

• Speed

• Distance travelled

• Acceleration

Answer explanation

In a velocity-time graph, the area under the line represents the total distance travelled. This is because distance is the integral of velocity over time, making it the correct choice.

What does a horizontal line in a velocity-time graph indicate?

• Deceleration

• Returning to start

• Acceleration

• Constant speed

Answer explanation

A horizontal line in a velocity-time graph indicates that the velocity is constant over time. This means the object is moving at a constant speed, not accelerating or decelerating.

What is the formula for average speed?

• Total time divided by total distance

• Final speed minus initial speed

• Initial speed plus final speed

• Total distance divided by total time

Answer explanation

The formula for average speed is calculated by dividing the total distance traveled by the total time taken. Therefore, the correct choice is 'Total distance divided by total time'.

What does a curved line in a displacement-time graph indicate?

• Constant speed

• Object is stationary

• Velocity is changing

• Object is returning to start

Answer explanation

A curved line in a displacement-time graph indicates that the object's velocity is changing. This means the speed or direction of the object is not constant, unlike a straight line which would indicate constant speed.

What is the formula for acceleration?

• a = v - u

• a = u + v

• a = v/t

• a = d/t

Answer explanation

The correct formula for acceleration is a = v - u, where 'a' is acceleration, 'v' is final velocity, and 'u' is initial velocity. This formula shows how acceleration is the change in velocity over time.

What happens if the speed is zero in a velocity-time graph?

• Object is accelerating

• Object is at rest

• Object is moving at constant speed

• Object is returning to start

Answer explanation

If the speed is zero on a velocity-time graph, it indicates that the object is not moving, meaning it is at rest. This is the correct choice, as acceleration and constant speed would imply a non-zero velocity.