Can you help me

Question

The apparatus shown in the figure below was used by Joule to measure the mechanical equivalent of heat. Work is done on the water by a rotating paddle wheel, which is driven by two blocks falling at a constant speed. The temperature of the stirred water increases due to friction between the water and the paddles. If the energy lost in the bearings and through the walls is neglected, then the loss in potential energy associated with the blocks equals the work done by the paddle wheel on the water. If each block has a mass of 1.30 kg and the insulated tank is filled with 200 g of water, what is the increase in temperature of the water after the blocks fall through a distance of 2.40 m?

Answer 1

Potential energy lost by blocks equals work done on the water. Assuming no energy is lost to the surroundings, the energy gained by water is equal to work done on it.

Therefore

m_bgΔh(blocks)=m_wcΔT (water)

m_bgΔh/m_wc=ΔT

Substituting:

the mass of 2 blocks=2.6kg

g=9.81ms^-2

distance fallen by 2 blocks=2x2.40=4.80m

m_w=200g=0.2kg

specific heat capacity of water is approximately = 4200JKg^-1K^-1(or °C)

2.6x9.81x4.8/(0.2x4200)=0.1457K (or ºC)

Since the least number of sig figs are determined by the mass of water, the answer should be given correct to 1 sig. fig. ∴

∴ ΔT is 0.1K (since this is a change in temperature, both K and °C will have the same value)