JEE Main202122 Jul 2021Morning ShiftPhysicsMathematics in PhysicsActual
Three particles P , Q and R are moving along the vectors A → = i ^ + j ^ , B → = j ^ + k ^ and C → = - i ^ + j ^ , respectively. They strike on a point and start to move in different directions. Now particle P is moving normal to the plane which contains vector A → and B → . Similarly particle Q is moving normal to the plane which contains vector A → and C → . The angle betwe
Correct answer
0
Step-by-step solution
Direction of P ,   v ^ 1 = ± A → × B → | A → × B → | = ± i ^ - j ^ + k ^ 3 Direction of Q ,   v ^ 2 = ± A → × C → | A → × C → | = ± 2 k ^ 2 = ± k ^ Angle between v ^ 1 and v ^ 2 , v ^ 1 · v ^ 2 v ^ 1 v ^ 2 = ± 1 3 ( 1 ) ( 1 ) = ± 1 3 ⇒ x = 3