Question

Calculate the intensity of IR radiation in W/m^2 projected by the concave mirror on a person 3.00 m away. Assume that the heating element radiates 1500 W and has an area of 100 cm^2, and that half of the radiated power is reflected and focused by the mirror.

a) 2500 W/m^2
b) 5000 W/m^2
c) 7500 W/m^2
d) 10000 W/m^2

Answer 1

To calculate the intensity of IR radiation projected by the concave mirror on a person 3.00 m away, we use the formula: Intensity = (Reflected Power/Area) / Distance^2. Using the given values of power, area, and distance, the intensity is calculated as 8333 W/m².

Step-by-step explanation:

To calculate the intensity of IR radiation projected by the concave mirror on a person 3.00 m away, we need to use the formula:

Intensity = (Reflected Power/Area) / Distance^2

Given that the heating element radiates 1500 W and has an area of 100 cm², and that half of the radiated power is reflected and focused by the mirror, we can calculate the intensity as follows:

Reflected Power = (1500 W / 2) = 750 W

Area = (100 cm²) * (1 m²/10000 cm²) = 0.01 m²

Distance^2 = (3.00 m)^2 = 9.00 m²

Now, substituting the values into the formula, we get:

Intensity = (750 W / 0.01 m²) / 9.00 m² = 8333 W/m²

Therefore, the intensity of the IR radiation projected by the concave mirror on a person 3.00 m away is 8333 W/m².