Question

Робітник піднімав вантаж масою 30 кг на висоту 5 м, використовуючи у першому випадку нерухомий блок, а у другому - рухомий. визначте для кожного з випадків: 1) силу, яку прикладав робітник, піднімаючи вантаж; 2) відстань, на яку переміщується вільний кінець мотузки перекинутої через блок; 3) роботу, виконану робітником.

Answer 1

Ответ:

Ответ разместил: Гость

m = ρ * V

В данном случае m = 54 г, ρ = 2,7 г/см³, поэтому

V = m / ρ = 54 / 2,7 = 20 см³

Объяснение:

Answer 2

Calculation of Force, Distance, and Work

To determine the force, distance, and work involved in lifting a 30 kg load to a height of 5 m using a fixed block and a movable block, we can use the principles of mechanics.

1) Force applied by the worker: - In the case of a fixed block, the worker needs to exert a force equal to the weight of the load to lift it vertically. The weight of the load can be calculated using the formula: weight = mass * acceleration due to gravity. - The acceleration due to gravity is approximately 9.8 m/s^2. - Therefore, the force applied by the worker in the first case is: force = weight = mass * acceleration due to gravity. - Substituting the given values, the force applied by the worker in the first case is: force = 30 kg * 9.8 m/s^2.

2) Distance moved by the free end of the rope: - In the case of a fixed block, the distance moved by the free end of the rope is equal to the height the load is lifted, which is 5 m.

3) Work done by the worker: - Work is defined as the product of force and distance. Therefore, the work done by the worker can be calculated using the formula: work = force * distance. - Substituting the given values, the work done by the worker in both cases is: work = force * distance.

Let's calculate the values for each case:

1) Case 1: Using a fixed block: - Force applied by the worker: force = 30 kg * 9.8 m/s^2. - Distance moved by the free end of the rope: distance = 5 m. - Work done by the worker: work = force * distance.

2) Case 2: Using a movable block: - Force applied by the worker: force = 30 kg * 9.8 m/s^2. - Distance moved by the free end of the rope: distance = 5 m. - Work done by the worker: work = force * distance.

Now, let's calculate the values for each case:

1) Case 1: Using a fixed block: - Force applied by the worker: force = 30 kg * 9.8 m/s^2 = 294 N. - Distance moved by the free end of the rope: distance = 5 m. - Work done by the worker: work = force * distance = 294 N * 5 m.

2) Case 2: Using a movable block: - Force applied by the worker: force = 30 kg * 9.8 m/s^2 = 294 N. - Distance moved by the free end of the rope: distance = 5 m. - Work done by the worker: work = force * distance = 294 N * 5 m.

Therefore, in both cases, the force applied by the worker is 294 N, the distance moved by the free end of the rope is 5 m, and the work done by the worker is 1470 J (Joules).