If the car is traveling at 83 km/h, will a friction force be required? If so, in what direction?

Question

Physics

Popcorn

21 August, 19:30

If the car is traveling at 83 km/h, will a friction force be required? If so, in what direction?

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Answers (2)

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Tommy Villegas · Answer 1

a friction force that opposes its movement

All this force has a direction opposite to that of the car

Explanation:

A car traveling at 83 km / h with constant speed has a friction force that opposes its movement, this force comes from several sources:

. - The air resistance that is proportional to the speed

/ - the resistance between the rubbers and the pavement that is constant

. - The internal friction of the different engine components

. - The formation of eddies due to the lack of aerodynamic shape of the car

All these forces must be counteracted the motor force

All this force has a direction opposite to that of the car

Simeon · Answer 2

Yes, a frictional force would be required parallel to the bank in the direction downwards the bank to prevent the car from moving off the bank.

Question:

A 1050-kg car rounds a curve of radius 72 m banked at an angle of 14°. If the car is traveling at 83 kmh, will a friction force be required? If so, in what direction?

Explanation:

When a car is to move round a curve with a particular radius, the centrifugal force due to rounding the curve would act on it, which would try to push it off the bank.

As a result of the inclined bank, a force as a result of gravity will act on it to prevent it from moving off the bank.

Fc = mv^2/r

Fw = mgsin14

Where;

Fc is the centrifugal force.

m = mass

Fw = force as a result of weight.

v = velocity of car

r = radius of circular path

g = acceleration due to gravity.

Looking at the two forces, due to the high speed of the car, low angle of inclination of the bank and relatively low radius of round path, the centrifugal force will be high than the force resulting from the weight to keep the car on the track.

Fc > Fw

Fc is directed out of the bank

Fw is try to keep the car on track

Therefore, when Fc > Fw and without frictional force acting inward (down the bank) to neutralise the centrifugal force the car would move off the bank and out of the round curve track. So frictional force is needed in the direction downwards the bank to keep the car on track.