Question

If a car at rest accelerates uniformly and attains a speed of $72km/hr$ in $10s$, then it covers a distance of:

• A. 50 m
• B. 100 m
• C. 200 m
• D. 400 m

Answer 1

Answer: (B)

Here : $u=0,v=72km/hr$
$=\frac{72\times 5}{18}$
$=20m/s$
$t=10sec$
The first equation of motion is
$v=u+at$
$20=0+a\times 10$
$\Rightarrow a=\frac{20}{10}$
$=2m/s^2$
The second equation of motion
$s=ut+\frac{1}{2}a{t}^2$
$=0\times 10+\frac{1}{2}\times 2\times (10{)}^2$
$=100m$