heat = mass * heat capacity of water * change in temperature
mass = 5.25 g
heat capacity of water = 4.186 joule/gram °C
Change in temperature = 62.8°C - 5.3°C = 57.5 °C
Plug in the values
heat = 5.25 g * 4.186 joule/gram °C * 57.5 °C = 1263.6 J
Rounded to two three significant figures, it is 1260 J of energy needed.
In terms of calories, the heat capacity of water is 1 calorie/gram °C. So do the plugging in all over again.
mass = 5.25 g
heat capacity of water = 1 calorie/gram °C
Change in temperature = 62.8°C - 5.3°C = 57.5 °C
heat = 5.25 g * 1 calorie/gram °C * 57.5 °C = 301.9 calories
Rounded to 3 significant figures, it is 302 calories
Q=SM∆T=4.18*5.25*(62.8-4.3)=1280 J
1280 J * (1 cal/4.18 J) = 307 cal