### Mechanical Equivalent of Heat Pre-lab Assignment

Your name: _____________________

Print this page, record your answers on it, and show it to your lab TF at the start of your lab session.

In this experiment you will investigate the idea of latent heat, and you will go on to investigate the mechanical equivalent of heat.

1. Run the simulation, which shows five graphs. If heat is being added to a sample of water at a constant rate, which graph best represents the plot of temperature vs. time over a two-minute period? Note that each graph shows the sample, which is initially solid, starting at -10°C and taking 10 seconds to reach 0°C.

You may find the following data helpful when deciding which graph is correct:

Specific heats for water: c_{liquid} = 1.0 cal/g °C and c_{ice} = c_{steam} = 0.5 cal/g °C

Latent heats for water: heat of fusion L_{f} = 80 cal/g and heat of vaporization L_{v} = 540 cal/g

Circle the correct graph below.

Graph 1 | |
Graph 2 | |
Graph 3 | |
Graph 4 | |
Graph 5 |

2. If heat is being added to the sample at a constant rate of 60 cal/s, what is the mass of the sample?