A student investigated how much energy from the Sun was incident on the Earth's surface at her location - AQA - GCSE Physics - Question 4 - 2018 - Paper 1

The equation linking energy transferred (E), power (P), and time (t) is given by:
$P = \frac{E}{t}$

To calculate the mean power, we use the equation:
$E = mc\Delta T$
Where:

• m = mass of water (1050 grams or 1.05 kg)
• c = specific heat capacity of water (4200 J/kg°C)
• ΔT = change in temperature (0.6 °C)
  Thus, the energy transferred is:
  $E = 1.05 imes 4200 imes 0.6 = 2646 J$
  Assuming the time taken for the temperature increase is 300 seconds, we can find power:
  $P = \frac{E}{t} = \frac{2646 ext{ J}}{300 ext{ s}} = 8.82 ext{ W}$

Using the equation:
$m = \frac{E}{c\Delta T}$
Substituting the values:
$m = \frac{2646 ext{ J}}{4200 imes 0.6} = 1.05 ext{ kg}$
Thus, the mass of water used is 1.05 kg.