Question

You're driving down the highway when a deer steps onto theroad 35m in front of you. Your reaction time before stepping on thebreaks is 0.5 seconds and the deceleration of the car is 10 m/s^2.What is the maximum speed that you could have and still not hit thedeer?

The above solution is incorrect.

Here is how I interpreted the problem.

entire distance is 35 meters

I--------------------------------------------------I

t=0 t=0.5 t=?

I--------------------I-----------------------------I

"coasting" ^beginsdeceleration

The answer should be ~21.5 m/s but I am not sure how to provethis