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 0.046kg - Edexcel - GCSE Physics - Question 2 - 2019 - Paper 1

To calculate the change in gravitational potential energy (

∆GPE), we can use the formula:

$$\Delta GPE = m \times g \times \Delta h$$

Where:

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

Now, substituting the values:

$$\Delta GPE = 0.046 \times 9.81 \times 2.05$$

Calculating this gives:

$$\Delta GPE = 0.046 \times 9.81 \times 2.05 \approx 0.93 \text{ J}$$

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

The formula for kinetic energy (KE) is given by:

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

Where:

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

Substituting in the values:

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

Calculating this gives:

$$KE = \frac{1}{2} \times 0.046 \times 12.25 \approx 0.28 \text{ J}$$

Thus, the kinetic energy of the ball when its speed is 3.5 m/s is approximately 0.28 J.