Question

Вычислите КПД рычага, с помощью которого груз массой 145 кг равномерно подняли на высоту 6 см. При этом к длинному плечу рычага была приложена сила 500 Н, а точка приложения этой силы опустилась на 0,3 м. РЕШИТЕ ЗАДАЧУ С ДАВНО И Т.П

Answer 1

вычислите КПД рычага,с помощью которого груз массой m=245 кгравномерно подняли на высоту h1=6 см=0,06 м,если при этом к длинному плечу рычага была приложена сила F=500 Н,а точка приложения этой силы опустилась на h2=0,3 м

полезная работа

А1=mg*h1

полная работа

А2=F*h2

КПД=А1/А2=mg*h1/F*h2=245*10*0,06 / (500*0,3)  *100%= 98 %

Answer 2

Calculating the Mechanical Advantage and Efficiency of a Lever

To calculate the mechanical advantage (MA) and efficiency (η) of the lever, we can use the following formulas:

Mechanical Advantage (MA): The mechanical advantage of a lever is given by the ratio of the length of the effort arm to the length of the load arm.

Efficiency (η): The efficiency of a lever is given by the ratio of the load distance to the effort distance, multiplied by 100 to express it as a percentage.

Given: - Load mass (m): 145 kg - Height lifted (h): 6 cm - Force applied (F): 500 N - Distance from the fulcrum to the point of force application (d1): 0.3 m

Calculating Mechanical Advantage (MA)

The mechanical advantage (MA) of the lever can be calculated using the formula: MA = Load Arm Length / Effort Arm Length

In this case, the load arm length is the height lifted (h), and the effort arm length is the distance from the fulcrum to the point of force application (d1).

Load Arm Length (L): Given that the load is lifted to a height of 6 cm (0.06 m).

Effort Arm Length (E): Given that the force is applied at a distance of 0.3 m from the fulcrum.

Now, we can calculate the mechanical advantage: MA = L / E

MA = 0.06 m / 0.3 m MA = 0.2

So, the mechanical advantage of the lever is 0.2.

Calculating Efficiency (η)

The efficiency (η) of the lever can be calculated using the formula: η = (Load Distance / Effort Distance) * 100

In this case, the load distance is the height lifted (h), and the effort distance is the distance from the fulcrum to the point of force application (d1).

Now, we can calculate the efficiency: η = (h / d1) * 100

η = (0.06 m / 0.3 m) * 100 η = 20%

So, the efficiency of the lever is 20%.

Therefore, the mechanical advantage of the lever is 0.2, and its efficiency is 20%.