Prescribed practical 4: personal power

Purpose

A guide to carrying out a practical to investigate personal power

To plan and carry out experiments to measure personal power, by measuring the time taken to climb a staircase or performing a number of step-ups to a platform.

Apparatus

1 short flight of stairs, a 50 cm rule, a stop clock, bathroom scales marked in kg.

Measuring the time taken to climb a staircase or performing a number of step-ups to a platform

Method

  1. Measure the persons mass in kg using bathroom scales.
  2. Convert it to weight using W = mg. This equals the upward force that will move up the stairs.
  3. Measure the height of 1 step using the 50 cm rule. Record in m in a suitable table. Repeat for two more steps and calculate the average height in m.
  4. Count the number of steps and record.
  5. Calculate the vertical height = number of steps x average height of 1 step.
  6. Calculate the work done = force x vertical height.
  7. Time the person running the stairs. Record in the table. After a rest repeat the experiment and calculate average time.
  8. Calculate the persons average power using: power = \frac{work~done}{time~taken}

Safety

HazardConsequenceControl measures
StepsFallThe flight of stairs should be short. Do not run up the steps too quickly. Go one step at a time.
StepsCollisionOnly one person at a time should carry out the experiment
StepsFall/CollisionWalk back down the steps and make sure nobody is running up