Question

The annual energy consumption of a High School is 100 million kWh. How much Uranium-235 is needed to produce this amount of energy in a nuclear power plant assuming 100% efficiency? (The weight loss (m) in the nuclear reaction is 0.2 g per 235 g of Uranium.)

Answer: 4700 g

Answer 1

The annual energy consumption of a High School is 100 million kWh.

Step 1. Convert kWh. To J

Energy= E=100 million kWh=3.6 x 10^14 J

Step 2.Calculate m

c=speed of light=3 x 10^8 m/s

E=mc^2

m=E/c^2

m = 3.6 x 10^14 J/ (3 x 10^8 m/s)²

= 0.004 kg = 4 g

Step 3. Calculate total mass of uranium required

The weight loss (m) in the nuclear reaction is 0.2 g per 235 g of Uranium.)

Means only 0.2g of Uranium in235 g of Uranium is converted into energy.

So, Total mass of uranium required= 4*235/0.2=4700 g