- #1

Radical

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- 0

## Homework Statement

A metal ball of mass 1kg is heated by means of a 20W heater in a room at 20°C. The temperature of the ball becomes steady at 50°C. (a) Find the rate of loss of heat to the surrounding when the ball is at 50°C. fa) Assuming Newton's law of cooling, calculate the rate of loss of heat to the surrounding when the ball is at 30°C. (c) Assume that the temperature of the ball rises uniformly from 20°C to 30°C in 5minutes. Find the total loss of heat to the surrounding during this period, (d) Calculate the specific heat capacity of the metal.

## Homework Equations

dT/dt= -k(T-Ts) where Ts is temperature of surrounding and T is temperature of the body.

Stefan's law ∆U= sigma e AT^4

## The Attempt at a Solution

For 1st part as the ball is in steady state at 50 °C hence amount of heat gained by ball = heat lost to the surroundings by radiation. Hence it is equal to 20 watt.

2nd part's the answer given is 20/3 watt but the answer I am getting is nowhere close.

I used the Stefan's law to find the answer.