Q. The distance-time graphs of a particle at time $t$ makes angle 45${^\circ}$ with the time axis. After two seconds, it makes an angle 60${^\circ}$ with the time axis. What is the average acceleration of the particle?
A) 1/2
B) $\sqrt{3}/2$
C) ($\sqrt{3} - 1$)/2
D) ($\sqrt{3} + 1$)/2
Explanation
(c) Initial velocity $u = \tan{45{^\circ}} = 1$
Velocity after $2$s, $v = \tan 60{^\circ}\ $=$\sqrt{3}$
$\therefore$ Average acceleration, $a_{av} = \frac{v - u}{t} = \frac{\sqrt{3} - 1}{2}$.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.