How much thermal energy is needed to raise the temperature of 4.0 kg of water from 25°C to 75°C?

Answer: Q = 840,000 J

Explanation: We will use the formula for heat to solve this problem Q = mc∆T, where the specific heat or "c" of water is 4200 J/kg°C. The change in temperature ∆T is equal to ∆T = (75°C-25°C) = 50°C

Q = 4.0 kg (4200 J/kg°C) (50°C)

= 840,000J

Cancel out the units of kg and °C so the remaining unit is in joules.

313.5 joule thermal energy is required