What is radiant heat? How do black and white coloured objects absorb heat?

A utensil, which is made of thick copper base, is placed on the gas burner to heat up water in it.

a) Describe briefly how heat is transferred:

i) From gas burner to water.

A utensil, which is made of thick copper base, is placed on the gas burner to heat up water in it.

a) Describe briefly how heat is transferred:

ii) Spread through water in the utensil.

A utensil, which is made of thick copper base, is placed on the gas burner to heat up water in it.

Explain why water would boil faster when a lid is placed on the utensil.

Observe the given diagram of a thermometer. The distance between $-{10}^{\mathrm{o}} \mathrm{C}$ and the ${110}^{\mathrm{o}} \mathrm{C}$ markings is $25 \mathrm{cm}$. If the length of the mercury thread is $15 \mathrm{cm}$ as shown in the figure, calculate the temperature measured by this thermometer.

Rama was boiling water in a kettle. Her mother asked what is the temperature of boiling water? She replied that it is $239° \mathrm{F}$.

Calculate the temperature of boiling water in degrees Celsius.