Welcome to practical physicsPracticle physics - practical activities designed for use in the classroom with 11 to 19 year olds
 

Power cycling up a hill

Class practical

Measuring the power used in cycling uphill.

Apparatus and materials

None listed

Health & Safety and Technical notes


This must be done in a safe place, such as the school grounds.

Procedure


a Students time themselves cycling up a rise.
 
b Determine the vertical distance climbed from an appropriate map or using a handheld GPS device. Alternatively, estimate the height with a sighting pole, a plumb line, and a large cardboard protractor.
 
c Knowing their own weight and estimating that of their bicycle, students calculate the output of 'useful' power.

 

Teaching notes


1 Useful power is calculated from:
 
'Useful power' = energy transferred/time taken
 
= (total weight in newtons x height rise)/time taken 

The mass of a bicycle is very unlikely to be less than 5 kg nor more than 20 kg. 10 kg would be an acceptable estimate, particularly as the mass of the student is probably of the order of 70 kg.
 
2 This experiment could be set as a class activity if a suitable site is available.

This experiment was safety-checked in January 2006

 

Related guidance


Power and energy