GCSE Physics: Forces and Motion 3

Question 1

What happens to the acceleration of an object if the resultant force is doubled but mass stays the same?

Accepted Answer

Acceleration doubles.

Answer

From F = ma, if F doubles and m is constant, then a must double to maintain the equation.

Question 2

A car brakes from 20 m/s to rest over 40 m. What is its deceleration?

Accepted Answer

5 m/s²

Answer

Using v² = u² + 2as: 0 = 400 + 2a×40, so a = -400/80 = -5 m/s² (deceleration of 5 m/s²).

Question 3

Which of the following best describes inertia?

Accepted Answer

The tendency of an object to resist changes in its state of motion.

Answer

Inertia is the tendency of an object to resist changes to its velocity, linked to Newton's First Law.

Question 4

On a velocity-time graph, what does a horizontal straight line indicate?

Accepted Answer

Constant speed (zero acceleration)

Answer

A horizontal line on a v-t graph means velocity is not changing, so acceleration = 0 and speed is constant.

Question 5

What is the stopping distance of a vehicle equal to?

Accepted Answer

Thinking distance + Braking distance

Answer

Stopping distance = thinking distance (distance travelled during driver's reaction time) + braking distance (distance travelled while brakes are applied).

GCSE - General Certificate of Secondary Education Practice Test

GCSE - General Certificate of Secondary Education Practice Test

GCSE Physics: Forces and Motion 3