Question

the direction of the resultant p vector and q vector having angle tita and alpha is angle made by r vector with p vector then​

Answer 1

Answer:

Resultant of two vector P and Q is R=P2+Q2+2PQcosθ. 

Where θ is the angle between the two vectors. 

As magnitude of Q is doubled the angle between the new resultant is 90o

Thus we get tan90o=P+2Qcosθ2Qsinθ

As tan90o=∞ we have P+2Qcosθ=0

P=−2Qcosθ

Now, R2=P2+Q2+2PQ2Q−P

R=Q