The car moves along the highway at a speed of 90 km / h. Determine the speed of the lowest point

The car moves along the highway at a speed of 90 km / h. Determine the speed of the lowest point of the wheel relative to the road surface.

Since the lowest point of the wheel is in contact with the highway, its speed relative to the highway will be zero at any time and for any wheel speed!

The point is that the points in contact with the surface replace each other. At the moment t₀ the point x₀ touches and its speed relative to the highway at this moment is equal to zero, at the moment t₁ the point x₁ touches and its speed is also equal to zero.

If we fix a certain point on the wheel rim, we will see that it moves along a curve called a cycloid.