Question

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

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

Answer 1

Answer: (B)

100 m

Answer 2

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