(1) 100⁰F to ⁰C
T(⁰C) = (T(⁰F)- 32) / 1.8
= (100⁰F - 32) / 1.8
T(⁰C) = 37.7⁰C
(2) 40⁰C to Fahrenheit (⁰F)
T(⁰F) = (T(⁰C) x 1.8) + 32
= 40⁰C x 1.8 + 32
= 72 + 32
T(⁰F) = 104⁰F
(3) 35⁰C to Kelvin
(T_K) = (T_0c)+ 273.15
= 35 + 273.15
(T_K) = 308.15 K
(4) 80⁰K to ⁰C
(T_0c) = (T_K) - 273.15
(T_0c) = 800 - 273.15
(T_0C) = -193.15⁰C

Specific latent heat of ice is very high (i.e.) 336 J/g.
1. Due to high specific latent heat of ice, snow on mountains do not melt as a whole, but melts gradually into water with the heat of the sun. If the specific latent heat of ice would not have been so high, all the snow would have melted very quickly and there would have been floods in the rivers.
2. All the water in lakes and ponds in cold places do not freeze all at the same time. If freezes slowly and keeps the surrounding moderate.
3. Drinks are cooled more effectively by ice pieces at 0⁰C and not by water at 0⁰C. This is because 1 g of ice takes away 336 J of heat from the drink to melt into water at 0⁰C.

Water has the highest specific heat capacity. So water absorbs a large amount of heat for unit rise in temperature. Thus water is used as a coolant in car radiators and factories to keep engine and other machinery parts cool. So water is a bad conductor of heat. Specific heat capacity of water is 4200J/kg^oC. So it is easy to raise the temperature. So it is possible to heat water easily while cooking.

Hot air balloons:
Air molecules at the bottom of the balloon get heated by a heat source and rise. As the warm air rises, cold air is pushed downward and it is also heated. When the hot air is trapped inside the balloon, it rises.
Breezes:
During day time, the air in contact with the land becomes hot and rises. Now the cool air over the surface of the sea replaces it. It is called sea breeze. During night time, air above the sea is warmer. As the warmer air over the surface of the sea rises, cooler air above the land moves towards the sea. It is called land breeze.
Winds:
Air flows from area of high pressure to area of low pressure. The warm air molecules over hot surface rise and create low pressure. So, cooler air with high pressure flows towards low pressure area. This causes wind flow.
Chimneys:
Tall chimneys are kept in kitchen and industrial furnaces. As the hot gases and smoke are lighter, they rise up in the atmosphere.

The minimum possible temperature is 0K. There is no limit to maximum temperature.

Temperature.

The amount of heat energy required to raise the temperature of 1 g water by 1⁰C is called one calorie.

Thermal capacity.

1. Mass of the body
2. Change in temperature of the body
3. Nature of the material of the body.

Heat capacity of ball = 50 J⁰C^-1
Heat lost Q = 2000 J
Fall in temperature t = ?
Heat capacity = \(\frac { Q }{ t } \)
50 = \(\frac { 2000 }{ t } \)
t = \(\frac { 2000 }{ 50 } \)
t = 40⁰C

Heat absorbed Q = 1,68,000 J
m = 2kg
Initial temperature t₁ = 30°C
Let final temperature t₂ = x⁰C
Rise is temperature \(\triangle \)t = (t₂ - t₁)
= (x- 30)⁰C
Specific heat capacity of water C = 4200 J kg^-1°C^-1
We know that Q = m x c x \(\triangle \)t
1,68,000 = 2 x 4200 x (x - 30)
x - 30 = \(\frac { 1,68,000 }{ 2\times 4200 } \)
\(\)x - 30 = 20
x = 30 + 20
= 50°C
So, the final temperature of water = 50°C

Mass of ice m = 200 g
Specific latent heat of fusion of ice L = 336 Jg^-1
Heat required Q = m L
= 200 x 336
Q = 67,200 J

Mass of iron m = 5 kg
Initial temperature t₁ = 30°C
Final temperature t₂ = 130°C
Rise is temperature \(\triangle \)t₂ = (t₂ - t₁) = 130 - 30 = 100°C
Specific heat capacity of iron c = 483 Jkg^-10C^-1
Q = m x c x \(\triangle \)t
= 5 x 483 x 100
= 2,41,500 J

(i) When steam hits our skin, it condenses to water and then cools down to the temperature of skin.
(ii) Now, the energy released will be due to latent heat and fall in temperature.
(iii) Whereas when boiling water hits our skin, there is no phase transition but only fall in temperature and the heat transferred to skin will be only due to cooling.
(iv) Also, the loss of energy that is released from steam hitting our skin occurs quickly and in a small localized area, therefore causing damage to our cells.