A 1200 N car is traveling on a level, straight road. The surface of the road is

Question

A 1200 N car is traveling on a level, straight road. The surface of the road is irregular, so when the brakes are applied, the frictional force between the tires and the road, and thus the car's acceleration, are not constants As a result, while the car is slowing down, the car's speed is given by the equation: V = 30 - 2t^2 - t, where t is in seconds and V in m/s. If friction is the only horizontal force acting on the car while slowing down, what is the acceleration of the car and the magnitude of the instantaneous frictional force acting on the car at t = 3 seconds after the brakes are applied?

Explanation / Answer

a= dV/dt = d(30-2t^2-t)/dt = -4t-1

a at t=3

= -4*3-1 = -13 m/s^2

F = ma

mass of car = 1200/9.8

=> F = (1200*13)/9.8 = -1591.83 N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.