Question

Imagine we cook an egg by immersing it into water which is boiled by an electric heater. The heater utilizes a current I =10 A at a voltage V = 120 volts for a time t = 120 s lf the change in energy of the newly-cooked egg over its raw torm is given by ΔEngg = 28.8 kJ, what is the amount of energy wasted in the process?

Answer 1

Answer:

Q' = 115.2 KJ

Explanation:

Given that

Current I = 10 A

Voltage = 120 V

Time t= 120 s

The energy supplied Q= V I t

Q= 10 x 120 x 120 J

Q= 144 x 1000 J

Q= 144 KJ

The change in the energy ΔEngg = 28.8 kJ

By using energy conservation

Q= Q' +  ΔEngg

Q'=Wasted energy

Now by putting the values in the above equation

144 = Q' + 28.8 KJ

Q' = 115.2 KJ

Therefore the waste energy will be 115 kJ.