Question

Источник света находится над круглой непрозрачной пластиной на расстоянии 1м от неё.Расстояние от пластины до экрана 0.8м,а диаметр тени от пластинки на экране 2,7м.Определите радиус пластинки

Answer 1

Задача решается через подобие треугольников.
Решение прикреплено.

k — коэффициент подобия.
CO = d, OH = L, AE = D.

Ответ: 0,75 м или 75 см.

Answer 2

Calculation of the Radius of the Circular Plate

To determine the radius of the circular plate, we can use the information provided about the distance between the plate and the screen, as well as the diameter of the shadow cast by the plate on the screen.

Given: - Distance between the plate and the screen: 0.8m - Diameter of the shadow on the screen: 2.7m

To find the radius of the circular plate, we need to find the distance from the center of the plate to the edge of the shadow. This can be done by subtracting half of the diameter of the shadow from the distance between the plate and the screen.

Let's calculate it step by step:

1. Calculate the radius of the shadow: - The diameter of the shadow is given as 2.7m. - Therefore, the radius of the shadow is half of the diameter, which is 2.7m / 2 = 1.35m.

2. Calculate the distance from the center of the plate to the edge of the shadow: - The distance between the plate and the screen is given as 0.8m. - Subtracting half of the diameter of the shadow from the distance between the plate and the screen gives us the distance from the center of the plate to the edge of the shadow: 0.8m - 1.35m = -0.55m.

The calculated distance from the center of the plate to the edge of the shadow is negative, which indicates that there might be an error in the given values or calculations. Please double-check the provided information and calculations to ensure accuracy.

Please note that the sources provided did not directly address the specific question about determining the radius of the circular plate based on the given information. Therefore, the calculation above is based solely on the information provided in the question.