4.1.1.4 Power

Question 1

Power:

Answer 1

• The rate at which energy is transferred or the rate at which work is done.
• It is how much energy is transferred per second.

Question 2

Calculating power:

Answer 2

• Power (Watts) = Energy transferred (J) / time (s)
• P = E/t
• Power (Watts) = Work done (J) / times (s)
• P = W/t

Question 3

What is an energy transfer of 1 joule per second equal to?

Answer 3

An energy transfer of 1 joule per second is equal to a power of 1 Watt

Question 4

Give two examples illustrating the definition of power:

Answer 4

• comparing two electric motors that both lift the same weight through the same height but one does it faster than the other
• comparing two people climbing to the top of the same hill but one runs up it and one walks up it

Question 5

What is the mechanical pathway the same as?

Answer 5

Work done