Question

A student takes 5 min to blow dry hair with a 2300 W blow dryer. How much energy dissipated by the blow dryer during this time?

Answer 1

The energy dissipated from the blow dryer = 690000 J or 690 kJ

Step-by-step explanation:

Electrical Energy: Is defined as the product of electric power and time.

The S.I unit of electrical energy is Joules (J)

Mathematically it is expressed as,

E = P×t................................... Equation 1

Where E = Electrical Energy, P = Electrical power, t = time.

Given: P = 2300 W, t = 5 min = 5×60 = 300 s.

Substituting into equation 1

E = 2300×300

E = 690000 J

E = 690000 J or 690 kJ.

Thus the energy dissipated from the blow dryer = 690000 J or 690 kJ