find angle between P vector and Q vector if resultant is given by R^2=P^2+Q^2.

Asked by anjalisharma83242 | 13th Aug, 2020, 11:20: AM

Expert Answer:

There are two vectors P and Q 
L e t space t h e space a n g l e space b e t w e e n space P with rightwards arrow on top space a n d space Q with rightwards arrow on top space b e space theta
R e s u l a t n t space v e c t o r space R space i s space g i v e n space a s space
R squared space equals space P squared plus Q squared plus 2 P Q cos theta space.... left parenthesis 1 right parenthesis
I t space i s space g i v e n space t h a t comma space
R squared space equals space P squared plus Q squared space.... left parenthesis G i v e n right parenthesis
S u b s t i t u t i n g space t h i s space e q u a t i o n space i n space e q u a t i o n space left parenthesis 1 right parenthesis comma space w e space g e t comma space
R squared space equals space R squared plus 2 P Q cos theta space
0 space equals 2 P Q cos theta space
T h u s comma space
cos theta space equals space 0
T h u s comma space
theta space equals space straight pi over 2 space o r space 90 degree space

Answered by Shiwani Sawant | 14th Aug, 2020, 12:58: PM