Question

A ball is projected from top of the table with initial speed $u$ at an angle of inclination $q$, motion of image of ball w.r.t ball

• A. Must be projectile
• B. Must be straight line and vertical
• C. Must be straight line and horizontal
• D. May be straight line, depends upon value of $\theta$

Answer 1

Answer: (C)

${\vec{V}}_{I_0}={\vec{V}}_I-{\vec{V}}_0$
${\vec{V}}_{I_0}=-u\cos \theta \hat{i}+u\sin \hat{j}-(u\cos \theta \hat{i}+u\sin \theta \hat{j})$
$V_{I_0}=-2u\cos \theta \hat{i}$
Straight line and horizontal