Question

The Sankey diagrams below show the energy transfers in two light bulbs. How much energy is wasted by light bulb 2?

Answer 1

Answer:

The amount of energy wasted by light bulb 2 = 70 J

Explanation:

Sankey diagrams are used to graphically indicate the proportional flow rate of a quantity

The labelled Sankey diagrams, here, indicate the energy transfers in two light bulbs, light bulb 1 and light bulb 2

From the labelled Sankey diagrams, we have;

For light bulb 1, the input energy = 80 J

The useful energy = 40 J

The wasted energy = 80 - 40 = 40 J

For  light bulb 2, the input energy = 80 J

The useful energy = 10 J

Therefore, the wasted energy = 80 - 10 = 70 J

The amount of energy wasted by light bulb 2 = 70 J.