Mechanical Advantage Formula: Definition, Unit and Important Questions

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Mechanical Advantage is the ratio of input force to output force. Mechanical advantage is used to assess the performance of a machine and to calculate the gain in force by the mechanical system. The term mechanical advantage is frequently used in reference to simple machines. It is used while studying the mechanism and working of a lever. Let’s have a look at the formula of mechanical advantage and some important questions related to mechanical advantage. 

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Introduction to Mechanical Advantage

Mechanical Advantage refers to the ratio of input force to output force.

Work refers to the amount of energy that transfers when a body is moved by an external force propagated in the direction of displacement. So, work done is the product of displacement or distance and force.

A large force applied at a small distance and a light force applied at a long distance can perform the same amount of work. So, the mechanical advantage is the ratio of input force to output force.

The extent to which friction and other factors are decreasing the actual work output of the machine determines the efficiency of the machine. A frictionless machine will have 100% efficiency. The ratio of the actual mechanical advantage and theoretical mechanical advantage is equal to the efficiency of the machine.

In an ideal case, the force of the object and the force applied to overcome the applied force are the same.

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Formula of Mechanical Advantage

Mechanical Advantage is the ratio of force applied to the object (input force) to the effort required to overcome the applied force (output force). So, the mechanical advantage formula is given by: 

\(MA = \frac{F_{B}}{F_{A}}\)

In this formula,

MA = Mechanical Advantage

FB = Force of the object

FA = Effort to overcome the applied force

Mechanical Advantage

Mechanical Advantage

Check Important Formula for Linear Momentum


Unit of Mechanical Advantage

Mechanical Advantage does not have a Unit. Both factors in the mechanical advantage formula are the same (force) and have the same unit, so mechanical advantage is a dimensionless parameter.


Things of Remember Based on Mechanical Advantage Formula

  • Mechanical Advantage refers to the ratio of input force to output force.
  • Mechanical Advantage is used to assess the performance of a machine. It is used for the calculation of gain in force by the mechanical system.
  • The term mechanical advantage is frequently used in reference to simple machines. It is used while studying the mechanism and working of a lever.
  • The ratio of the actual mechanical advantage and theoretical mechanical advantage is equal to the efficiency of the machine.
  • The formula of mechanical advantage is \(MA = \frac{F_{B}}{F_{A}}\). In the formula, MA stands for Mechanical Advantage. FB stands for Force of the object and FA stands for Effort to overcome the applied force. Mechanical Advantage does not have a Unit.
  • In an ideal case of mechanical advantage, the force of the object and the force applied to overcome the applied force are the same.

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Sample Questions Based on Mechanical Advantage Formula

Ques: Describe an ideal case of Mechanical Advantage. (2 Marks)

Ans: In an ideal case of mechanical advantage, the force of the object and the force applied to overcome the applied force are the same.

Ques: Mechanical Advantage is the ratio of input force to output force. Explain.  (2 Marks)

Ans: Work is the amount of energy that transfers when a body is moved by an external force propagated in the direction of displacement. So, work done is the product of displacement or distance and force. A large force applied at a small distance and a light force applied at a long distance can perform the same amount of work. So, mechanical advantage is the ratio of input force to output force.

Ques: What is the value of Mechanical Advantage when the force is 500 Newton force is needed to overcome a load of 1000 Newton?  (3 Marks)

Ans: In the above case, we need to find the mechanical advantage of the machine.

Effort to overcome the applied force = 1000 N = FB

Force of the object = 500 N = FA

Mechanical Advantage = FB / FA

Mechanical Advantage = 1000 / 500

Mechanical Advantage = 2

The value of Mechanical Advantage is 2.

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Ques: What is the effort needed to overcome the applied force if the force of the object is 200 N and Mechanical advantage of the machine is 5?  (3 Marks)

Ans: In the above case, we need to find the effort needed to overcome the applied force.

Mechanical Advantage = 5 = MA

Force of the object = 200 N = FA

So to find the effort to overcome the applied force (FB):

\(MA = \frac{F_{B}}{F_{A}}\)

FB = MA × FA

FB = 5 × 200

FB = 1000 N

So the effort to overcome the applied force is 1000 N.

Ques: What is the force required to overcome a load of 720 Newton if Mechanical advantage of the lever is 9? (3 Marks)

Ans: In the above case, we need to find the force of the object.

Mechanical Advantage = 9 = MA

Effort to overcome the applied force = 720 N= FB

So to find the force of the object (FA):

\(MA = \frac{F_{B}}{F_{A}}\)

9 = 720 / FA

FA = FB / MA

FA = 720/ 9

FA = 80 N

So, the force of the object is 80 Newton.

Ques: What is the value of Mechanical Advantage when the force is 150 Newton force is needed to overcome a load of 900 Newton? (3 Marks)

Ans: In the above case, we need to find the mechanical advantage of the machine.

Effort to overcome the applied force = 900 N = FB

Force of the object = 150 N = FA

Mechanical Advantage = FB / FA

Mechanical Advantage = 900 / 150

Mechanical Advantage = 6

The value of Mechanical Advantage is 6.

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Ques: What is the effort needed to overcome the applied force if the force of the object is 300 N and Mechanical advantage of the machine is 6? (3 Marks)

Ans: In the above case, we need to find the effort needed to overcome the applied force.

Mechanical Advantage = 6 = MA

Force of the object = 300 N = FA

So to find the effort to overcome the applied force (FB):

\(MA = \frac{F_{B}}{F_{A}}\)

FB = MA ×FA

FB = 6 × 300

FB = 1800 N

So,the effort to overcome the applied force is 1800 N.

Ques: What is the force required to overcome a load of 500 Newton if Mechanical advantage of the lever is 10? (3 Marks)

Ans: In the above case, we need to find the force of the object.

Mechanical Advantage = 10 = MA

Effort to overcome the applied force = 500 N= FB

So to find the force of the object (FA):

\(MA = \frac{F_{B}}{F_{A}}\)

10 = 500 / FA

FA = FB / MA

FA = 500 / 10

FA = 50 N

So, the force of the object is 50 Newton.

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