## Wednesday, August 26, 2020

### Specific Heat Capacity

Specific Heat Capacity of a matter is defined as amount of heat required to rise 1dgree Celsius of temperature of 1kg mass. If m is mass of body, H is amount of heat absorbed by the body, dt is temperature difference i.e. t2-t1, and s is specific heat capacity of body then,

H = msdt is the relation among them.

Q. If 2kg water is heated from 20-30 degree Celsius how much heat is absorbed by water ? given that specific heat capacity of water is 4200J/kg/degree Celsius

Answer: here, m = 2kg, dt = 30 -20 =10 degree Celsius s =4200

So, H = msdt = 2x4200x10 = 84,000J

Q. Mercury of specific heat capacity 140J/Kg0C is heated from 150C to 400C by applying heat of 17,500J, what should be the mass of mercury?

Q. Mercury of specific heat capacity 140J/Kg0C is heated from 150C to 400C by applying heat of 17,500J, what should be the mass of mercury?

Here,     m = ?

S = 140J/Kg0C

dt = 40 – 15 = 250C

H = 17,500J

We know, msdt  = H

Or, mx140x25 = 17,500

0r, m =17,500/3500

Therefore m = 5Kg

Q. If 10Kg sand requires heat of 1.6x105J to rise its temperature from 140C to 340C, find specific heat capacity of sand. (left for students, answer in comment)

Q. Why water is used as cooling agent?

Ans: Water is cheap, abundant and it has higher value of specific heat capacity. So it is used as colling agent.