Question

On which height could you lift a car of mass (m=800kg) if you would completely use the energy from cooling 1kg of water from temperature of 30 degrees Celsius to 20 degrees Celsius? Specific heat capacity of water is: c=4,186*10^3 J/kgK? (It is also given that the correct answer is 5m)

Answer 1

We have:

$$\begin{array}{l} Mgh = cm \Delta T \Rightarrow \\ \Rightarrow h = \frac{cm \Delta T}{Mg} = \frac{4.186 \cdot 10^3 \cdot 1 \cdot 10}{800 \cdot 9.8} = 5 \text{ m}. \end{array}$$

Answer: 5 meters.