Question

Проекционный экран массой 1,8 кг и высотой 2 м сворачивается автомеханизмом. какую работу совершило устройство?

Answer 1

M = 1.8 кг - масса экрана
h = 2м - высота подъёма
g = 10 м/c² - ускорение свободного падения
А = ? - работа по подъёму экрана
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А = mgh
A = 1.8 · 10 · 2 = 36 (Дж)
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Ответ: 36 Дж

Answer 2

Calculating the Work Done by the Projection Screen Mechanism

To calculate the work done by the projection screen mechanism, we can use the formula:

Work (W) = Force (F) × Distance (d) × cos(θ)

Where: - Force (F) is the force applied by the mechanism to lift the screen. - Distance (d) is the distance over which the force is applied. - θ is the angle between the force and the direction of motion.

Given: - Mass of the projection screen (m) = 1.8 kg - Height of the screen (h) = 2 m - Acceleration due to gravity (g) = 9.81 m/s^2

Calculating the Force Required to Lift the Screen

First, we need to calculate the force required to lift the screen. This can be done using the formula:

Force (F) = mass (m) × acceleration due to gravity (g)

Substituting the given values: F = 1.8 kg × 9.81 m/s^2

F = 17.658 N

Calculating the Work Done

Now, we can calculate the work done by the mechanism to lift the screen. Since the screen is being lifted vertically, the angle (θ) between the force and the direction of motion is 0 degrees, and cos(0) = 1.

Using the formula: Work (W) = Force (F) × Distance (d) × cos(θ) W = 17.658 N × 2 m × 1

W = 35.316 joules

Therefore, the work done by the projection screen mechanism to lift the 1.8 kg screen to a height of 2 m is 35.316 joules.