The resultant of vectors P⃗ and Q⃗ is perpendicular to P⃗. If P=Q/2, find the angle between P⃗ and Q⃗ in degrees.
Physics · Mathematical tools and vector · Vector
NEET JEE Mains

Question

The resultant of vectors P⃗ and Q⃗ is perpendicular to P⃗. If P=Q/2, find the angle between P⃗ and Q⃗ in degrees.

G1 Physics · Accepted Answer

Perpendicular condition gives P+Q cosθ=0. Thus cosθ=−P/Q=−1/2, so θ=120°.