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Work


  • 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

  • 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