This question was a two parter(adsbygoogle = window.adsbygoogle || []).push({});

A car of mass 422 kg travels around a flat,

circular race track of radius 178 m. The co-

efficient of static friction between the wheels

and the track is 0.135.

The acceleration of gravity is 9:8 m=s2 :

What is the maximum speed v that the car

can go without flying off the track?

I got vmax as 15.3458 m/s

The same car now travels on a straight track

and goes over a hill with radius 200 m at the

top.

What is the maximum speed that the car

can go over the hill without leaving the road?

I'm not sure how to go about tackling that problem, I tried just substituting 200 m in for the radius but that doesn't work.

This one was also a two parter

A civil engineer is asked to design a curved

section of roadway that meets the following

conditions:

With ice on the road, when the coefficient of

static friction between the road and rubber is

0.23, a car at rest must not slide into the ditch

and a car traveling less than 50 km=h must

not skid to the outside of the curve.

At what angle should the road be banked?

I got the angle to be 12.95

What is the minimum radius of curvature of

the curve?

I tried using tan(theta)=v²/rg, but again I was wrong.

Any help would be greatly appreciated.

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# Homework Help: Having trouble with friction, incline problems

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