Question

There are two force vectors, one of 5 N and other of 12 N. At what
angle the two vectors be added to get resultant vector of 17 N, 7 N
and 13 N respectively
09, 180° and 90
09.90* and 180
0°, 90° and 90
180". O' and 90°

Answer 1

Answer:

Here, R=A+B

or R.R=(A+B).(A+B)

or R2=A2+B2+2ABcosθ  where θ be the angle between vectors A and B. 

When R=17N⇒172=52+122+2(5)(12)cosθ or cosθ=1=cos0 or θ=0o 

When R=7N⇒72=52+122+2(5)(12)cosθ or cosθ=−1=cos180 or θ=180o 

When R=13N⇒132=52+122+2(5)(12)cosθ or cosθ=0=cos90 or θ=90o