What is the speed of a car if its wheel, whose radius is 30 cm, makes 10 revolutions per second.

R = 30 cm = 0.3 m.
t = 1 s.
N = 10.
V -?
Vehicle speed V will be equal to the linear speed of wheel rotation.
Let’s find the linear speed of rotation of the wheel. The linear speed of rotation is determined by the formula: V = L / T, where L is the distance traveled by a point of the wheel in one revolution, T is the time of one revolution.
T = t / N.
The point of the wheel passes in 1 revolution the circumference L = 2 * п * R.
V = 2 * п * R * N / t.
V = 2 * 3.14 * 0.3 m * 10/1 s = 18.84 m / s.
Answer: vehicle speed V = 18.84 m / s.