Question

How do i solve this? i am unsure of the correct answer

Answer 1

Given:

The magnitude of two forces, F₁=2.4 N

And F₂=1.8 N

The angle between the two forces, θ=90°

To find:

The magnitude of the third force.

Step-by-step explanation:

When the two forces acting are perpendicular two each other, the magnitude of the net force acting on them can be easily calculated by the triangle law of vector edition.

Thus the magnitude of the net force is given by,

`F_n=\sqrt[]{F^2_1+F^2_2+2F_1F_2\cos \theta}`

On substituting the known values,

`\begin{gathered} F_n=\sqrt[]{2.4^2+1.8^2+2*2.4*1.4*\cos90\degree} \\ =\sqrt[]{2.4^2+1.8^2+0} \\ =3.0\text{ N} \end{gathered}`

In order for the object to not move, the magnitude of the third force must be equal to the magnitude of the net force acting on the object.

Final answer:

The magnitude of the third force must be 3.0 N

Thus the correct answer is option C.