Question

A 100 g piece of granite and a 100 g piece of lead are placed in an oven that is at 100°C. The initial temperature of the pieces are 25°C. After a couple of minutes, neither one is at 100°C, but which one is warmer? Which one will reach 100°C first? How much energy will it take for both of the objects to reach 100°C?

Answer 1

specific heat data ( J/gm.deg.c) : granite =0.79, lead = 0.128

specific heat is the amount of energy required to rise the temperature of 1 gm of substance by 1 deg.c.

substances with a low specific heat capacity get heated quickly.

since specific heat of granite is more than lead, lead reaches 100 deg.c faster than granite when kept in oven

energy required = mass* specific heat* temperature difference

energy required for lead = 100*0.128*(100-25) joules =960 joules

energy required for granite= 100*0.79*(100-25) joules =5925 joules