ty2

Activity #10: Work and Power

Objectives:

· Find out how much work you do when walking up stairs.

· Find out how much power you use.

Materials:

· Phone (timer)

· Ruler or measuring tape

Theory: Work happens when you use force to move something.

When climbing stairs, the force is your weight, so:

· = your mass (kg)

· = 9.8 m/s²

· = height climbed (m)

· W= work (Joules, J)

Power tells how fast you do work.

· = power (Watts)

· = time (seconds)

Procedure：

1. Measure your mass (kg).

2. Measure the height of one step.

3. Count how many steps you climb. Try to climb 1–3 full flights of stairs (about 20–40 steps total).

4. Use a timer to record how long it takes you to go up the stairs. Try 2–3 times and use your fastest safe time.

Calculate the following:

1. Your total height climbed, using the equation:

2. Your work done, using the equation:

3. Power, using the equation:

Answer the following questions:

4. Who did more work: a heavier or lighter person? Why?

5. Who had more power: someone faster or slower? Why?

6.What could make your results a little inaccurate?