Question

the greatest and least resultant of two fotces are respectively 17kN and 3KN. Determime the angle between the two forces when their resultant

$\sqrt{149}$
kN​

Answer 1

Answer:

=>θ=π/2 or 90°

Explanation:

A vector +B vector = 17kN ( maximum resultant)--- eq i

A vector -B vector =3kN ( minimum resultant)--- eq ii

adding equation i and ii

2(A vector )=20kN

A vector =10kN

Then B vector= 7kN

for angle we know that

R²=(A vector )²+(B vector)² +2(A vector )(B vector)Cosθ

149=100+49+2×10×7 Cosθ

=>140Cosθ =0

=>Cosθ=0

=>θ=π/2