The coffee machine heats water from 20 °c to 90 °c.
the power output of the coffee machine is 2.53 kw.
the specific heat capacity of water is 4200 j/kg °c.
calculate the mass of water that the coffee machine can heat in 14 seconds.

The mass of water that the coffee machine can heat in 14 seconds is equal to 0.1204 kg.

Given:

Initial temperature of water =

Final temperature of water =

Power of coffee machine =

Specific heat capacity of water =

Time for which water is heated =

Mass of water = m = ?

Power is defined as work done in unit time. Let the heat energy be Q. Power (P) is defined as where t denotes the time for which energy is supplied. Q can be rewritten as:

......................(1)

Formula for Heat energy is given by

Q = m×c×Δt ........................................(2)

where:

Q = Heat energy (in J)

m = mass of the substance being heated in grams(kg)

c = the specific heat of the substance in J/(kg.°C)

Δt = Change in temperature (in °C)

Δt = (Final temperature - Initial temperature) = .......................(3)

From (1) and (3), solving equation (2) for m;

Q = m×c×Δt

The mass of water that the coffee machine can heat in 14 seconds is equal to 0.1204 kg.