Question

the total energy of the lamp is 9 units. the lamp is turned on and converts all of the electrical energy into 7 units of radiant energy and a small amount of heat. how many units of heat energy are there? 6 units 2 units 1 unit 3 units

Explanation:

Step1: Recall energy conservation

The total energy is conserved, so total energy = radiant energy + heat energy.

Step2: Calculate heat energy

Let \( H \) be heat energy. We know total energy \( T = 9 \) units, radiant energy \( R = 7 \) units. Using \( T=R + H \), we solve for \( H \): \( H=T - R=9 - 7 = 2 \) units.

Answer:

2 units (corresponding to the option "2 units")