Question

If a car at rest accelerates uniformly to a speed of $144km/h$ in $20$ second, it covres a distance of :-

• A. $20m$
• B. $400m$
• C. $1440m$
• D. $2980m$

Answer 1

Answer: (B)

$400m$

speed of car after 20 sec. $=144km/h=144\ast \frac{5}{18}m/s=40m/s$
$v=u+at40=0+20aa=2m/s^2$
Distance covered $s=ut+1/2a{t}^2=0\ast 20+\frac{1}{2}\ast 2\ast {20}^2=400m$