Question

9a driver has a reaction time of 0.50 s , and the maximum deceleration of her car is 6.0 m/s2 . she is driving at 20 m/s when suddenly she sees an obstacle in the road 50 m in front of her.

Answer 1

The distance traveled during the reaction time is
d₁ == (20 m/s)*(0.50 s) = 10 m

The deceleration is  6.0 m/s²
The distance, d₂, traveled until the car comes to a complete stop is given by
(20 m/s)²  - 2*(6.0 m/s²)*(d₂ m) = 0
d₂ = 400/12 = 33.333 m

The total distance traveled before the car comes to rest is
d₁ + d₂ = 10 + 33.333 = 43.333 m
Because 43.333 m is less than 50 m, the car will not hit the object.

Answer:
The car comes to a stop before reaching the object. It will not hit the object.