Question

Three forces acting at a point keep it in equilibrium . If the angle between two of the forces, 3 N and 3 Ni
s 120°, then the third force is
A.
3N
B.
5N
C.
1N
D.
12N​

Answer 1

Answer:

A. 3 N

Explanation:

Working with the two forces, we can find the resultant by breaking them into x and y components as follows:

Sum of forces in X-axis = 3 - 3sin30°

= 3 - 1.5 = 1.5 N

Sum of forces in Y-axis = 3cos30°

= 2.6 N

Resultant = √(1.5^2 + 2.6^2) = √9 = 3 N

This will be the third force acting at the point to make the resultant zero and bring the object in equilibrium.