Question

A car start from rest and accelerates uniformly to a speed of $180km{h}^{-1}$ in $10s$. The distance covered by the car in this time interval is?

• A. $500m$
• B. $250m$
• C. $100m$
• D. $150m$
• E. $200m$

Answer 1

The correct option is B

$250m$

Step 1: Given data

Initial velocity, $u=0m/s$

Final velocity, $$\begin{gathered} v=180km{h}^{-1}=180\times \frac{1000m}{3600s} \\ \Rightarrow v=50m{s}^{-1} \end{gathered}$$

Time taken, $t=10s$

Step 2: Find the acceleration $a$

$$\begin{gathered} a=(v-u)/t \\ a=50/10 \\ a=5m{s}^{-2} \end{gathered}$$

Step 3: Find the distance covered by the car

The distance covered by the car is given by

$$\begin{gathered} s=ut+(1/2)a{t}^2 \\ s=0+(1/2)\times 5\times {\left(10\right)}^2 \\ s=250m \end{gathered}$$

Hence, option B is correct.