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Home » 1.0 kg of water is contained in a 1.25 kW kettle. Calculate the time taken for the temperature of water to rise from 25° C to its boiling point 100° C. Specific heat capacity of water = 4.2 J g-1 K-1.
1.0 kg of water is contained in a 1.25 kW kettle. Calculate the time taken for the temperature of water to rise from 25° C to its boiling point 100° C. Specific heat capacity of water = 4.2 J g-1 K-1.
Calorimetry | Class 10 | ICSE | Physics | Selina
1.0 kg of water is contained in a 1.25 kW kettle. Calculate the time taken for the temperature of water to rise from 25° C to its boiling point 100° C. Specific heat capacity of water = 4.2 J g-1 K-1.

Solution:

We know that the Heat energy = Power × time

Also we can write in the following manner –

Heat energy = mc(change in temperature)

Therefore, we can write => mc(change in temperature) = Power × time

According to the question, mass of the water is 1000g and

Change in temperature is (100-25) = 75

Upon substituting values, we get –

1000 × 4.2 × 75 = 1250 × time

Therefore, time = (1000 × 4.2 × 75) / 1250

time = 315000 / 1250 = 252 sec

Or, time = 4 min 12 sec

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