Question

An electric saw operates at a potential difference of 120 V and draw a current of 9.5 A. If it takes 40 S to make a cut, calculate the amount of electrical energy used.

Answer 1

Potential difference is the same as voltage. The formula for calculating power is expressed as

P = IV

where

P = power

I = current

V = voltage

From the information given,

V = 120

I = 9.5

Thus

P = 120 x 9.5 = 1140

The formula for calculating energy is expressed as

Energy = Power x time

Given that time = 40s, then

Energy = 1140 x 40

Energy = 45600 J