Question

Two forces act on a point object as follows 100N at 170°and 100N at 50°.find their resultant

Answer 1

Angle between the two forces are:

$170\degree-50\degree=120\degree$

So ,

Resultant force ,

$F=\sqrt{F_1^2+F_2^2+2F_1F_2\cos\theta}$

Now,

$F_1=F_2=100\ N$

And

$\theta=120\degree$

So,

$F=\sqrt{100^2+100^2+2×100×100×\cos120\degree}\\=100\ N$

Direction:

Since both forces are equal so the direction of resultant force will be exactly midway between these two forces

So angle will be $\frac{(170+50)}{2}=110\degree$