Question

Two equal forces F have a resultant of 1.5F. Find the angle between the forces?

Answer 1

Answer:

$R^{2}$=$F^{2}$+$F^{2}$+2$F^{2}$cosA

Explanation:

R=1.5F=3/2F

soo,

(3/2F)^2=2$F^{2}$ +2$F^{2}$cosA

(3/2F)^2-2$F^{2}$=2$F^{2}$cosA

9/4$F^{2}$ -2$F^{2}$ =2$F^{2}$cosA

$\frac{9-8}{4} F^2$  =2$F^{2}$cosA

1/4$F^{2}$=2$F^{2}$cosA

1/8$\frac{F^2}{F^2} =1$   =cosA

1/8=cosA

A=$cos^{-1}$1/8