A 750 kg car moving at 25 m/s has Kinetic Energy. To stop the car requires work. On snowy roads, the force of friction that can stop a car reduces to only about 725 N.
a. How much work must be done to stop the car? (Hint: What is the car's kinetic energy?)
b. How far will the car travel before stopping if the only force stopping it is friction between the tires and the road?

a. By the work-energy theorem, the total work required to stop the car is equal to the change in its kinetic energy,

W = 0 - 1/2 (750 kg) (25 m/s)² ≈ -230 kJ

b. The car covers a distance x as it stops such that

W = (-725 N) x   ==>   x ≈ 320 m

b) 10 minutes

girls stopped for 10 minutes.

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14