Question

A 3kW kettle boils water in 4 minutes. Does this use more electrical energy than a 150W fridge left on 1 hour?

Answer 1

Answer:

The kettle used more electrical energy

Explanation:

We need to find the appliance that used more electrical energy.

To solve this problem, we need to find the amount of electrical energy used by both appliances.

For the kettle;

 Power consumed  = 3kW

  Time  = 4minutes

    Electrical energy  = Power x time

    Convert 4min to hr;

              60min  = 1hr

               4min   = $\frac{4}{60}$   = $\frac{1}{15}$hr

  Electrical energy  = 3 x  $\frac{1}{15}$ = 0.2kwh

For the fridge;

  Power consumed  = 150W = 0.15kW

   Time  = 1hr

     

     Electrical energy  = 0.15kW x 1hr = 0.15kWh