Question

A piece of lead with a specific heat capacity of 126J/kg°C is given 5000J of energy to heat it from 20°C to 250°C. What was the mass of the piece of lead?

Answer 1

Answer:

m = 0.172 [kg]

Explanation:

To solve this problem we must use the expression of thermal energy that relates the heat to the mass, the specific heat, and the temperature differential.

Q = m*Cp*(T_f - T_i)

where:

m = mass [kg]

Cp = specif heat = 126 [J/kg*C]

Q = 5000 [J]

T_f = final temperature = 250 [C]

T_i = initial temperature = 20 [C]

m = Q/ (Cp*(T_f - T_i))

m = 5000/ (126*(250 - 20))

m = 0.172 [kg]