A copper container of mass 100g contains 500g of water. A steel paddle of mass 85g stirs the water. A pulley system operates the paddle.

A) the mass (15kg) drops 2,4m, turning the steel paddle. Assume heat lost to surrounding is negligible.
1. Find the energy transfered to the container,water and paddle.
2. Find the rise in temperature of the water.
3. Assume that the rise in temperature of the steel paddle is the same as that of the water when the energy is transferred from the pulley system to the water. Find the energy needed to raise temperature of 1kg steel paddle by 1 degree Celsius.

1 answer

a. gravitational energy=heatinwater, assuming the dropping mass did not gain velocity.

b. masscopper*cc*deltaT+masspaddle*c*deltaT+masswater*cw*deltaTemp=total energy in