IF a vehicle (any vehicle) is travelling at 100 km/h...?

Question

...what speed are the tires travelling at the contact point with the road? Please explain your reasoning.

Answer 1

100km/ hour is 28m/s.

This speed is with reference to an observer on the road.

With reference to an observer on the road, the path of any point of the tyre is a cycloid. (Assuming rolling without slipping)

There fore any point has horizontal component and vertical component of speed at any point on the cycloid path.

At the instant when a point is in contact with road, its vertical speed is v sin a;
the horizontal speed is given by v (1-cos a) where ‘a’ is angle made by the radius of the wheel to the vertical direction.

When a = 0, both the horizontal and vertical component is zero.
When a = 90 degree, both the vertical and horizontal component is v.
When a = 180 degree, vertical component is zero, horizontal component is 2v.
When a =270 degree, vertical component is (-) v, horizontal component is v.
When a =360 degree, both the horizontal and vertical component is zero
.
.

Answer 2

The tire will be stationary at the point of contact. The speed the tire is rotating will depend on the size of the tire

Answer 3

any point of the tire will be the same speed because they are moving in rotaional motion example for that a man standing in france will be the same speed for another standing in china for earth, that's for rotational speed, but if you want to know straight speed it's will be zero.

Answer 4

keepergary is the best answer. He explained why. Phil and Sue O didn't even give a speed.

Answer 5

What is your reference point? An onlooker? The car? Be less vague.

Answer 6

It will be zero unless there is a slippery surface, you brake, drift or accelerate

Answer 7

Zero! Unless, of course, you are skidding.

Answer 8

The length of the tire as if it was a strip.

Answer 9

zero.