Question

If a $5kg$ body falls to the ground from a height of $30$ metres and if all its mechanical energy is converted into heat, the heat produced will be

• A. $350cal$
• B. $150cal$
• C. $60cal$
• D. $6cal$

Answer 1

The correct option is A $350cal$

$350cal$

$Q=mgh$

$=5\times 9.8\times 30=1470J$

$1cal=4.2J$

$=\frac{1470}{4.2}=350cal$