- #1

aceXstudent

- 14

- 0

P: A person driving her car at 50km/h approaches an intersection just as the traffic light turns yellow. She knows that the yellow light lasts only 2.0s before turning to red, and she is 30m away from the near side of the intersection. Should she try to stop or should she make a run for ti? The intersection is 15m wide. Her car's max deceleration is -6.0m/s^2, whereas it can accelerate from 50 to 70 km/h in 6.0s. Ignore the length of her car and her reaction speed.

Must find out how long it takes for the car to reach the end of the intersection. First, find the acceleration from 50-70km/h.

After conversions...

(19.4m/s-13.9m/s)/6.0s= 0.917m/s^2

Now must find time it took for her to reach the end.

d= 45m

Vo=13.9m/s

a=0.917m/s^2

t=?

How do I find t and how do I find out if she can make the braking distance?