Parallelogram of Forces Questions and Answers with Quiz

What is a resultant force?

Which law of forces states that the resultant of two forces can be represented by the diagonal of a parallelogram?

How is the resultant force of more than two intersecting forces calculated?

According to which law of forces can the resultant be represented by the third side of a triangle taken in opposite order?

If the resultant force makes an angle α with the horizontal, how can it be determined?

Which law states that if a number of forces are represented by sides of a polygon taken in order, then their resultant can be represented by the closing side of the polygon?

Resultant Force

A single force that produces the same effect as all the given forces acting on a body

Laws of Forces

Three laws to determine the resultant force:
- Law of Parallelogram: if two forces acting simultaneously on a particle are represented in magnitude and direction by the two adjacent sides of a parallelogram, then their resultant is represented in magnitude and direction by the diagonal of the parallelogram
- Law of Triangle: if two forces acting simultaneously on a particle are represented in magnitude and direction by the two sides of a triangle taken in order, then their resultant is represented in magnitude and direction by the third side of the triangle taken in opposite order
- Law of Polygon: if a number of forces acting simultaneously on a particle are represented in magnitude and direction by sides of a polygon taken in order, then their resultant is represented in magnitude and direction by the closing side of the polygon taken in opposite order

Finding Resultant Force

For more than two intersecting forces, resolve all forces horizontally and vertically
Resultant force (R) is given by: R = √(Horizontal component^2 + Vertical component^2)
If the resultant (R) makes an angle α with the horizontal, then: tan(α) = Vertical component / Horizontal component

Test your knowledge on how to determine the resultant force using the parallelogram law of forces. Learn how to calculate the resultant force of two or more forces acting on a body.