AP Lab for Wednesday

Please read this so we can do this lab quickly tomorrow.

Power Lab

In this lab we will determine the power you deliver in raising yourself with and without the average back pack one story. You will calculate the change in potential energy you gain and the time it takes you to gain it. Finding the ratio will give you the power you deliver running up the stairs.

Facts you may need:

1 horsepower = 746watts

1lb mass = .454 kg

g =9.8 N/kg

P=W/Dt

W= DKE +DPE. Find KE using v found from distance = (Dh/cos (45)) +2

Procedure:

Choose a timer, a runner, and a starter for your group. Starter stays at the bottom and timer stands at the top. . Make sure your timer can here you when the runner starts.

Measure the change in height from the first to the second floor.

Measure the runner’s weight in lbs and the backpack’s

Runner ______lb Pack _____ lb convert these to kg for use in finding Joules and Watts

The runner will make 4 runs:

one at a walk without the pack;

one at a walk with the pack;

one at top speed with the pack

one at top speed without

Calculate the power for each run in watts ( 1 watt = 1 J/s). Analyze the effects of change in speed and work done on the power.

Is the kinetic energy is negligible compared to the gain in potential energy?