Calculate Frictional Force Driving Up Inclined Hill - 4270kg Car

[jbowser]

Okay, I have tried this problem 13 times, used up 13 sheets of paper and I just don't know how to do this. Do ask me what I don't know, because I just don't understand physics, and no one I have asked can explain it to me in a way that I can understand it. Please I hope someone can expain how to set this up and find my answer.

You are sitting in a stopped car on a hill that is inclined at an angle of 52.7o with respect to the vertical. The combined mass of you and the car is 4270 kg.

You push down on the gas pedal and begin to travel up the hill. After 17.3 s have elapsed, your height has increased by 194 m.

Assuming that the frictional force was constant as you drove up the hill, what was the magnitude of the frictional force from the road on the car's tires?

 

[member 553083]

To solve this problem, you need to use Newton's Second Law and the equation F=ma. Newton's Second Law states that "the rate of change of momentum of a body is proportional to the net force acting on it and takes place in the direction of the force". In this case, the force that is acting on the car is the friction force from the road on the car's tires, so we can re-write the equation as Ffriction = ma. We can then solve for the magnitude of the frictional force by rearranging the equation: Ffriction = m(a) = (4270 kg)(a). Now, since you know the acceleration (a) of the car, you can substitute that into the equation. Since the height has increased by 194 m after 17.3s have elapsed, the acceleration of the car must be 11.2 m/s2. Therefore, the magnitude of the frictional force from the road on the car's tires is 47,744 N.