Efficiency of a single fixed pulley is 85%.what effort is needed to lift a load of 85kgf using it?

To calculate the effort needed to lift a load using a single fixed pulley, you need to consider the efficiency of the pulley system.

Efficiency is given as the ratio of output work to input work, expressed as a percentage. In this case, the efficiency of the single fixed pulley is given as 85%.

To calculate the effort needed, you can use the formula:

Effort = (Load / Efficiency)

Effort = (85 kgf / 0.85)
Effort = 100 kgf

Therefore, the effort needed to lift a load of 85 kgf using a single fixed pulley with an efficiency of 85% is 100 kgf.

To determine the effort needed to lift a load using a single fixed pulley, you can use the equation:

Efficiency = (Output work / Input work) * 100%

Given that the efficiency of the pulley is 85% and the load is 85 kgf (kilogram-force), you need to find the effort required.

First, let's understand the concept of work. In physics, work is defined as the force applied to an object multiplied by the distance over which the force is applied. The units for work are Newton-meters (Nm) or Joules (J).

In this case, we need to consider the input work and output work in relation to the fixed pulley. The input work is the effort applied, and the output work is the work done on the load.

Since the pulley is fixed, the direction of the force applied and the load is the same. Therefore, the input force (effort) and output force are equal.

Now, let's calculate the effort needed to lift the load using the single fixed pulley.

Efficiency = (Output work / Input work) * 100%

We know that the efficiency is 85%, which can be written as 0.85.

Efficiency = 0.85

Given that the output work (Woutput) is equal to the input work (Win) because the forces are equal, we can rewrite the equation as:

0.85 = (Woutput / Win) * 100%

Dividing both sides of the equation by 100%:

0.85 / 100% = Woutput / Win

Simplifying:

0.85 = Woutput / Win

Since Woutput = Win, we can rewrite the equation as:

0.85 = Woutput / Woutput

We can conclude that the input work (Win) is equal to the output work (Woutput).

Now, let's calculate the effort needed (input force) to lift the load of 85 kgf using the fixed pulley.

Input work (Win) = Input force (effort) * Distance

Output work (Woutput) = Output force * Distance

Since the distances for the input and output work are the same, we can eliminate the distance from the equation.

0.85 = (Output force / Input force)

To find the input force (effort):

Input force = Output force / 0.85

Given that the load is 85 kgf, the output force is equal to the load force. Therefore:

Input force = 85 kgf / 0.85

Input force = 100 kgf

So, the effort needed to lift a load of 85 kgf using the single fixed pulley is 100 kgf.

M*g = 85*9.8 = 833 N. = Force of load.

Effort = 833/0.85 =