Q. If a car at rest accelerates uniformly to a speed of 144 $km/h$ in 20 $s$. Then it covers a distance of
A) $20\ m$
B) $400\ m$
C) $1440m$
D) $2880\ m$
Explanation
(b) Here $v = 144\ km/h = 40m/s$
$v = u + at \Rightarrow 40 = 0 + 20 \times a \Rightarrow a = 2\ m/s^{2}$
$\therefore s = \frac{1}{2}at^{2} = \frac{1}{2} \times 2 \times (20)^{2}$=$\ 400\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.