Question

A person decides to loose weight by eating only cold food. A 1 kg piece of apple pie yields 1500 kJ of energy when eaten. It its specific heat is 1.7 kJ/kg °C, how much less energy is its energy component at 25°C than at 100°C?

Please show work.

Answer 1

here,

mass of apple peice , m = 1 kg

specific heat of apple , Ca = 1.7 KJ/kg = 1700 J.kg C

T1 = 100 degree C

T2 = 25 degree

the less energy component at 25 degree C than at 100 degree C , dQ = m * Ca * ( T1 - T2)

dQ = 1 * 1700 * ( 100 - 25) J

dQ = 127500 J = 127.5 KJ