Question

Calculate the power of a person that does 8kJ of work in 4 hours

Answer 1

Answer:

Explanation:

Energy used is power multiplied by time.

Power is energy used divided by time

8 kj is 8000 j

4 hours is 240 minutes

240 minutes is 14400 seconds

8000j divided by 14400 is 0.55 recurring, measured in watts

Answer 2

$\text{Power,}~ P = \dfrac{\text{Work done}}{\text{Time}}\\\\\\~~~~~~~~~~~~~=\dfrac{8 \times 1000~J}{4 \times 3600~ s}\\\\\\~~~~~~~~~~~~~~=\dfrac{80}{144}\\\\\\~~~~~~~~~~~~~~=0.56~ W$