# Resultant of 2 forces – Common mistake

A force of 3.0 N and a force of 4.0 N act on an object at the same time. Which of the following forces cannot be the resultant force on the object?

A) 0.5 N     B) 3.5 N     C) 4.0 N     D) 5.0 N

Solutions: A) 0.5 N
To achieve maximum resultant force from 3.0 N and 4.0 N, both forces have to be parallel and in the same direction. Hence the maximum resultant force will be 3 N + 4 N = 7 N

To achieve minimum resultant force from 3.0 N and 4.0 N, both forces have to be parallel and in the opposite direction. Hence the minimum resultant force will be 4 N – 3 N = 1 N

Hence any magnitude of resultant force between 1 N and 7 N is possible as the 2 forces can be positioned at an angle to each other.

Therefore, only option (A) cannot be the resultant force on the object as it is less than the minimum resultant force of 1 N.

### 3 thoughts on “Resultant of 2 forces – Common mistake”

1. Thanks a lot mate this has solved a great problem of mine ….. It was really help full.
Keep it up sir ..

• You are welcome 🙂

• You are welcome!