How do you calculate the energy needed to heat 4 kg of water from 25oC to 45oC?
m Cp (T2-T1)
Cp = 4190 Joules/(kg deg K)
To calculate the energy needed to heat a substance, you can use the specific heat capacity formula. The specific heat capacity (c) is the amount of energy required to raise the temperature of 1 kg of a substance by 1 degree Celsius.
For water, the specific heat capacity is approximately 4186 J/kg·°C.
So, to calculate the energy needed (Q) to heat 4 kg of water from 25°C to 45°C, you can use the following formula:
Q = m * c * ΔT
Where:
Q: Energy needed (in Joules)
m: Mass of the water (in kg)
c: Specific heat capacity of water (in J/kg·°C)
ΔT: Change in temperature (in °C)
Substituting the given values into the equation:
m = 4 kg
c = 4186 J/kg·°C
ΔT = (45°C - 25°C) = 20°C
Q = 4 kg * 4186 J/kg·°C * 20°C
Q = 334,880 J (rounded to the nearest whole number)
So, the energy needed to heat 4 kg of water from 25°C to 45°C is approximately 334,880 Joules.