Question

Three bodies of the same material and having masses of m, m and 3m are at temperatures of 40°C, 50°C and 60°C respectively. If the bodies are brought in thermal contact, the final temperature will be:  

Options

• 45°C

• 54°C

• 52°C

• 48°C

Answer 1

54°C

Explanation:

Let the temperature of bodies kept in thermal contact be θ_mix.

For bodies made up of the same material

θ_mix = `("m"_1θ_1 + "m"_2θ_2 + "m"_3θ_3)/("m"_1 + "m"_2 + "m"_3)`

∴ θ_mix = `("m" xx 40 xx "m" xx 50 + 3"m" xx60)/("m" + "m' + 3"m")`

= `270/5`

= 54°C