Question

The temperature of a block of iron increases by 2 K when 3760 J of heat are added to it. What is the mass of the block of iron? The specific heat capacity of iron is 470J/kg*K.

5 kg

4 kg

2 kg

3 kg

Answer 1

The amount of heat needed to increase the temperature of a substance by
`\Delta T` is:

`Q=m C_s \Delta T`
where
Q is the amount of heat
m is the mass of the substance
Cs is the specific heat capacity of the substance

`\Delta T` is the variation of temperature

We know the heat added to the block of iron, Q=3760 J, its variation of temperature,
`\Delta T=2 K`, and the specific heat capacity of iron,
`C_s = 470 J/(kg K)`, so we can re-arrange the previous formula to find the mass of the block:

`m= (Q)/(C_s \Delta T)= (3760 J)/((470 J/(kgK))(2 K))=4 kg`