Question

Identical amounts of heat are applied to 50 g blocks of lead, iron, and copper, all at an initial temperature of 25 °C. Which block will have the largest increase in temperature?

Answer 1

Lead will have the largest increase in temperature.

Step-by-step explanation:

Given:

The heat supplied to three equal mass blocks is same. The initial temperature of each block is 25 °C. The three blocks are of different material- iron, copper and lead.

The heat supplied to a body is directly proportional to its mass, specific heat capacity and the increase in temperature and is given as:

`Q=mc\Delta T\\Q\rightarrow Heat\\m\rightarrow mass\\c\rightarrow \textrm{Specif heat capacity}\\\Delta T\rightarrow \textrm{increase or decrease in temperature}`

Now, for the given question, for the three blocks,
`Q\ and\ m` are same. Thus, specific heat capacity is inversely proportional to change in temperature.

This means that the block that has the highest value of
`c` has the least increase in temperature,
`\Delta T` and the one that has the least value of
`c` has the largest increase in temperature.

Specific heat capacity of the three blocks are:

Lead:
`c=0.128\ J/gK`

Copper:
`c=0.386\ J/gK`

Iron:
`c=0.450\ J/gK`

Thus, lead has the least value of
`c`. So, it will have the largest increase in temperature.