MHT CET202019 Oct 2020Morning ShiftPhysicsMathematics in PhysicsActual
The resultant of two vectors P and Q is R . When the direction of Q is reversed, the resultant is given by S . Which one of the following is true for vectors R and S ?
Options
- AR ²- S ²= ( P ²+ Q ² )
- BR ²- S ²=2( P Q )
- CR ²+ S ²=4( P Q )
- DR ²+ S ²=2 ( P ²+ Q ² )
Correct answer
D. R ²+ S ²=2 ( P ²+ Q ² )
Step-by-step solution
(B) Given, P+Q=R After reversing direction of R , we gel array l r=-P-Q S=-P-Q array So let angle between P and Q be Q So resurtants. array l R²=p²+Q²+2 P Q ...(1) s²=p²+Q²-2 P Q ...(2) array Adthing equation (1) and (2) R²+S²=2 (P²+Q² ) So, the corvect answer is R²+s²=2 (p²+Q² )