Five equal forces of 10N each are applied at one point and all are lying in a plane. If the angles between any two are equal, the resultant force is

Solution:

Given that number of forces = 5 

Magnitude is equal.

$\left|\overrightarrow{a}\right|=\left|\overrightarrow{b}\right|=\left|\overrightarrow{c}\right|=\left|\overrightarrow{d}\right|=\left|\overrightarrow{e}\right|$

and angle between any two is equal 

So they form regular pentagon as shown.

We get

$\therefore \overline{a}$+$\overline{b}$+$\overline{c}$+$\overline{d}$+$\overline{e}$=$\overline{0}$