AIM

To study the relationship between the temperature of a hot body and it time of cooling by plotting curve.

THEORY

According to Newtons Law of Cooling

dQ/dt ∝ (T – To)

For an body of mass m , specific heat s , and temperature T kept in surrounding of temperature To

Q =msT

Now the rate of cooling

dQ/dt =ms dT/dt

ms dT/dt ∝ (T -To)

Since the mass and the specific heat of the body are taken as constant ,the rate of change of temperature with time can be written as

dT/dt ∝ (T- To)

The above equation explains that, as the time increase ,the difference in temperatures of the body and surroundings decreases and hence ,the rate of fall of temperature also decrease.

PROCEDURE

2/3 of calorimeter is filled with hot water about 80°c place the calorimeter in side the wooden block .The space between the wooden block and calorimeter is filled with cotton . Close the wooden box . wooden box is closed with a led . a  thermometer is suspend in the hot water.  stir it continuously  to make it cool. when temperature falls to 70ºc start the stop watch note the temperature reading in every 5 minute . continue the observation until the temperature become a constant.

 

Newtons cooling curve

RESULT

the cooling curve of the liquid is plotted the temperature falls quickly in the beginning and then slowly as the difference of temperature goes on decreasing. this is the agreement with newtons law of cooling.

Thanks for joining me!

Good company in a journey makes the way seem shorter. — Izaak Walton