In Joule's Experiment, an Insulated Container Contains 20 Kg of Water

Multiple Choice

In Joule's experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms-2 . Neglecting the heat capacity of agitator, the temperature of water (in °C) is

A) 40.5
B) 34.4
C) 26.8
D) 25