8) Which of these is the equation for work done? A work done = force ÷ distance moved in direction of force B work done = force × distance moved in direction of force C work done = force ÷ distance moved at right angles to direction of force D work done = force × distance moved at right angles to direction of force (b) A ball has a mass of 0.046 kg - Edexcel - GCSE Physics - Question 8 - 2019 - Paper 1

To find the change in gravitational potential energy (ΔGPE), use the formula:

where:

• m = 0.046 kg (mass of the ball)
• g = 9.81 m/s² (acceleration due to gravity)
• h = 2.05 m (height)

Calculating:

Thus, the change in gravitational potential energy is approximately 0.93 J.

The kinetic energy (KE) can be calculated using the formula:

where:

• m = 0.046 kg (mass of the ball)
• v = 3.5 m/s (speed of the ball)

Calculating:

Thus, the kinetic energy of the ball is approximately 0.28 J.

From Figure 15, the estimated maximum height of the ball after the first bounce is approximately 1.5 m.

The ball does not bounce back to its starting height of 2.05 m due to energy losses during the bounce. Factors such as:

• Air resistance
• Deformation of the ball and the surface
• Dissipation of energy as heat

These factors convert some of the potential energy into other forms, resulting in a lower rebound height.

Observing Figure 16, the maximum height reached after each bounce decreases progressively as the bounce number increases. This trend indicates that with each successive bounce, the ball loses more energy, likely due to inelastic collisions and energy dissipation, resulting in a lower apex height.