O Avoid An Accident A Driver Steps On The Brakes To Stop A 950 Kg Car Traveling At 60 Km/H. If The Braking Is Distance Is 25 M, How Much Force Is Need

o avoid an accident a driver steps on the brakes to stop a 950 kg car traveling at 60 km/h. if the braking is distance is 25 m, how much force is needed to stop the car

 

Good Day...

Problem:

To avoid an accident a driver steps on the brakes to stop a 950 kg car traveling at 60 km/h. if the braking is distance is 25 m, how much force is needed to stop the car.

Given Data:

Velocity initial = 60 km/hr

60 km/hr × 1000 m/ 1km × 1 hr / 3600 s = 16.667 m/s

Velocity final = 0 m/s (stop)

d (distance) = 25 meters

a (acceleration) = ? unknown

Solution:

First: We will solve for acceleration with the formula Vf^2 = Vi^2 + 2 ad

To solve for a (acceleration) we can use a = Vf^2 -  Vi^2 / 2d

a = Vf^2 -  Vi^2 / 2d

   = (0 m/s)^2 - (16.667 m/s)^2  / 2 × 25 m

   = - 277.789 m^2/s^2 / 50 m

   = -5.556 m/s^2 (decelerating)

Second: The force needed to stop the car is the mass times acceleration:

m (mass)  = 950 kg

a (acceleration) = -5.556 m/s^2

F = ma

  = 950 kg × -5.556 m/s^2

  = - 944.44 kg.m/s^2

 =  - 944.44 N

Answer:

The force needed stop the car is    - 944.44 N

Hope it helps...=)