The intensity of light incident on a 5m by 3m screen with a power of 300W is 20 W/m², which is found by dividing the power by the area of the screen.
Step-by-step explanation:
The question asks to calculate the intensity of light incident on a screen with a given power and area. Intensity is defined as the power per unit area. To find the intensity, you can use the formula:
I = P / A
Where I is the intensity in watts per square meter (W/m²), P is the power in watts, and A is the area in square meters.
In this case, the power P is given as 300 W, and the area A of the rectangular screen can be calculated by multiplying its length and width:
A = length × width = 5 m × 3 m = 15 m²
Now we can calculate the intensity:
I = P / A = 300 W / 15 m² = 20 W/m²
Therefore, the intensity of light incident on the screen is 20 W/m².