# At what speed should the car go so that the pebble stuck in the tire that fell off its wheel at point A

March 31, 2021 | education

| **At what speed should the car go so that the pebble stuck in the tire that fell off its wheel at point A would hit the same point on the wheel from which it came off? Wheel radius 20 cm.**

It is natural to solve the problem in the frame of reference associated with

by a car, where the points of the wheel rim move in a circle with a speed v. In this system, the pebble will begin to move vertically upwards at exactly this speed. For the full time of its flight t = 2v / g, the wheel must complete an integer N number of revolutions, i.e. t = N * (2п * R) / V.

Hence V = √ (N * п * g * R) = 2.5 * √N.

There are quite a few suitable speed values.

Even with N = 100, we get a very real value of the speed (about 90 tkm / h).

Answer: V = √ (N * п * g * R).

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.