Question

Two forces 10N and 20N are inclined at an angle of 60° to each other. Find the resultant force by graphical and by mathematical methods. If the two forces are now made to be inclined 120° to each other, find the magnitude of the new resultant force.

Answer 1

Answer:

$10 \sqrt{7}$

and

$10 \sqrt{3}$

Explanation:

resultant=

$\sqrt{ {10}^{2} + {20}^{2} + 2 \times 10 \times 20 \cos(60) }$

=

$\sqrt{500 +400 \times 1 \div 2 }$

=

$\sqrt{700}$

new resultant=cos 120 instead of cos 60

=

$\sqrt{500 - 200}$

=

$\sqrt{300}$