Question

which action best demonstrates the transformation of mechanical energy to heat energy? (digesting a meal; burning a candle; rubbing hands vigorously; melting a piece of ice in sunlight)

Explanation:

• Digesting a meal: Converts chemical energy (in food) to other forms, not mechanical to heat.
• Burning a candle: Converts chemical energy (in wax) to light and heat, not mechanical to heat.
• Rubbing hands vigorously: The mechanical energy from the motion of rubbing is converted into heat energy (hands get warm), which matches the transformation.
• Melting a piece of ice in sunlight: Converts solar (light) energy to heat to melt ice, not mechanical to heat.

Answer:

C. rubbing hands vigorously