4. A 1,800 kg car is traveling at 40 m/s when the driver slams in the brakes to stop the car. The brakes apply a maximum force of 24,600 N. How far will the car travel while coming to a stop?
O 117 meters
0 58.5 meters
O 29.3 meters

The brakes do

W = ∆K = 0 - 1/2 (1800 kg) (40 m/s)² = -1.44 MJ (megaJoules)

of work on the car to stop it. They apply a negative force since the braking opposes the car's forward displacement, so the car stops over a distance x such that

W = (-24.6 kN) x   ==>   x ≈ 58.5 m

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.