Question

In a two-dimensional motion of a particle, the
particle moves from point A, with position vector
7, to point B, with position vector P. If the
magnitudes of these vectors are, respectively,
= 3 and r, = 4 and the angles they make with
the x-axis are e, = 75° and e, = 15°, respectively,
then find the magnitude of the displacement
vector.
2
be
Х​

Answer 1

Answer:

Explanation:

15

13−−√

17

15−−√

Answer :

B

Solution :

Displacement =AB−→−, angle between r→1 and r→2 is θ=75∘−15∘=60∘

From (Figure), AB2=r21+r22−2r1r2cosθ

=32+42−2×3×4cos60∘=13  

⇒AB=13−−√