Question

A body of mass 5 kg falls from a height of 30 metre. If its all mechanical energy is changed into heat, then heat produced will be

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

Answer 1

Answer: (A)

350 cal

Answer 2

$W = JQ$ ⇒ $mgh = J \times H$

⇒ $Q = \frac{mgh}{J} = \frac{5 \times 9.8 \times 30}{4.2} = 350cal$