Question

Problems 1. To what temperature will 4500 J of work raise 1.0 kg of water initially at 10 degrees Celsius? 2. How much work (in joules) must a person do to offset eating a 700 Cal piece of cake? 3. A water heater can generate 8300 kcal/hr. How much water can it heat from 12 degrees Celsius to 67 degrees Celsius in 1 hour? 4. An automobile cooling system holds 60 liters of water. How much heat (in kilocalories) does it absorb if its temperature rises from 26 degrees Celsius to 77 degrees Celsius?

Answer 1

1)Solution-

The specific heat of water = 4186 J/kg*C°
Now 4186 Joules of heat energy will increase the temperature of 1 kg of water 1°C

Now the heat energy to increase temperature = mass * Sp.Ht * ∆T
4500 = 1.0 * 4186 * ∆T
=>∆T = 4500 / (1.0 * 4186) = 1.075°

Final temperature = 10.0 + 1.075

= 11.075°