Question

Two forces 20N and 5N are acting at an angle 60deg

Answer 1

Explanation:

here, their sum is √(20²+5²+2*20*5*cos[60°])

which is √400+25+100

= √525= 5√21

and their difference is √(20²+5²-2*20*5*cos[60°])

= √425-100

= √325 = 5√13

:)