Question

Martin rides his motorcycle at 20 m/s. suddenly he sees a row of stones

Answer 1

Answer: Yes

Explanation:

Given

Martin initial speed is $u=20\ m/s$

Stones is at 170 m ahead

Deceleration $a=2\ m/s^2$

Using the equation of motion $v^2-u^2=2as$

Insert the values

$0-20^2=2\times (-2)s\\s=\dfrac{400}{4}\\\\s=100\ m$

So, it took 100 m to stop completely. Hence martin will be able to stop in time.