A girl ran to the top of some stairs - AQA - GCSE Physics - Question 2 - 2022 - Paper 1

To calculate the power (P), we use the formula:

$P = \frac{\text{work done}}{\text{time}}$

Given that the work done is 1800 J and the time taken is 1.44 s, we can substitute:

$P = \frac{1800}{1.44}$

Calculating this yields:

$P = 1250 ext{ W}$

To find the kinetic energy (E_k), we use the formula:

$E_k = 0.5 \times \text{mass} \times (\text{speed})^2$

Substituting the values:

• Mass = 70 kg
• Speed = 2.0 m/s

Thus, we calculate:

$E_k = 0.5 \times 70 \times (2.0)^2$

Calculating gives us:

$E_k = 0.5 \times 70 \times 4 = 140 ext{ J}$