Question

The reaction time for an automobile driver is 0.5 sec. If the automobile can be decelerated at $5m/s^2$ calculate the total distance travelled in coming to stop from an initial velocity of 20 m/s after a signal is observed

• A. 50 m
• B. 12.77 m
• C. 16.83 m
• D. 19.65 m

Answer 1

The correct option is A 50 m

$\begin{array}{c}S=20\times 0.5+\frac{v^2}{2a}\\ \Rightarrow S=10+\frac{20\times 20}{10}\\ =10+40\\ =50m\end{array}$

Hence option $A$ is the correct answer.