A car is moving at 25.0m/s on a straight highway lane. 10.0m in front of the car is a van that is travelling with the same speed. The van’s driver suddenly hits the brakes to avoid an obstruction, slowing down at a rate of 9.00m/s². The car’s driver reacts 0.85s later, when he realizes the van’s tail lights are on. Assume that the brakes are the same quality and the car decelerates at the same constant rate as the car.

Question

a. Calculate how far the van is going to travel before it stops.
b. Calculate how much distance the car needs to come to a stop.
c. Is the car going to rear-end the van?
d. If the car’s driver is distracted because of his phone (!) and reacts 1.20s later, instead of the 0.85s, how much distance will elapse before they collide?
e. How fast is the car going just as the collision happens, in the case described by part (d)?

Answer 1

lmfao the professor at uncc checks this bro

Answer 2

im guessing you have the answer then?

Answer 3

ughh just give me the equations i need to solve the problem pleasee

Answer 4

a. Calculate how far the van is going to travel before it stops.
***vf^2=vo^2 + 2a d. solve for d.
b. Calculate how much distance the car needs to come to a stop.
vf^2=vo^2 + 2ad. Now to this d, add vo*.85
c. Is the car going to rear-end the van?***does the car go 10 m further than the van? If so, it hits it.
d. If the car’s driver is distracted because of his phone (!) and reacts 1.20s later, instead of the 0.85s, how much distance will elapse before they collide?***same equations.
e. How fast is the car going just as the collision happens, in the case described by part (d)? set the distance = 10+van distance, and then solve for Vf

Answer 5

so for part b, it's the same answer as a, but i add (25m/s + 0.85s)?