- Work is done when a force moves an object or changes its direction. It is measured in Joules.
- Rule for Work
Work(Joules) = Force(Newtons) X Distance(metres)
W = F X d
- Example to calculate Work
Question: A weightlifter raises weights of 2000 Newtons from the floor to a height of 2 metres. How much work has been done?
Answer:
W = F X d
= 2000 X 2
= 4000 Joules
- Power is the rate at which work is done. Power is measured in Watts.
- Rule for Power
Power (Watts) = Work (Joules) / Time (seconds)
P = W / T
- Example of calculating Power
Question: A weightlifter lifted 2000 Newtons to a height of 2 metres. This 4000 Joules of work. What is the power output if this was done in 2 seconds?
Answer:
P = W / T
= 4000 / 2
= 2000 Watts