1. 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 Combined Science - Question 1 - 2019 - Paper 1

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

$$ΔGPE = m × g × Δh$$

Where:

• m = mass of the ball = 0.046 kg
• g = acceleration due to gravity ≈ 9.81 m/s²
• Δh = height lifted = 2.05 m

Substituting the values:

$$ΔGPE = 0.046 imes 9.81 imes 2.05$$

Calculating this gives:

$$ΔGPE ext{ ≈ } 0.932 ext{ J}$$

Thus, the change in gravitational potential energy is approximately 0.932 J.

The formula for kinetic energy (KE) is:

$$KE = \frac{1}{2} m v^2$$

Where:

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

Now substituting the values:

$$KE = \frac{1}{2} × 0.046 × (3.5)^2$$

Calculating this gives:

$$KE ≈ \frac{1}{2} × 0.046 × 12.25 = 0.28 ext{ J}$$

Therefore, the kinetic energy of the ball when it is moving at 3.5 m/s is approximately 0.28 J.