Why is angular velocity multiplied by radius equal to linear velocity!

Why is angular velocity multiplied by radius equal to linear velocity!

The use of international units is uniform

Why is linear velocity equal to angular velocity x radius
C circle = 2 π R L = n π R / 180 linear velocity = L / time angular velocity = n / time
Angular velocity × radius = linear velocity → n / time × r = L / time → n × r = L is not right
For example, the angular velocity of the earth is 15 ° / h, the equatorial radius = 6378 ㎞ and the equatorial line velocity = 1670 ㎞ / h
According to the line speed = 531.5 ㎞ / h, it's just a π difference. Why

Arc length = radian * radius if the radius is constant, the derivative of arc length is linear velocity and the derivative of radian is angular velocity

What is the relationship between angular velocity and radius
The angular velocity is inversely proportional to the radius, and the linear velocity is directly proportional to the radius

The angular velocity of each point on the object rotating around the same axis is equal, and the linear velocity is proportional to the radius
The linear speed of each point on the two rims of belt drive is equal, and the angular speed is inversely proportional to the radius. That is, the big wheel turns slowly, and the small wheel turns fast

The relation between radius and radius
Directly proportional or inversely proportional
The formula also needs to be changed

Linear velocity = angular velocity * radius v = w * r

If the vibration period of a spring oscillator is 0.2 seconds and the distance is 80 cm in 4 seconds, what is the frequency and amplitude of the oscillator

v=1/T=50Hz
There are 4 / 0.2 = 20 cycles in 4 seconds, and the amplitude A = 80 / 20 = 4cm

When a spring oscillator is in harmonic motion, if its amplitude is doubled and its frequency is reduced to half of its original value, how does its total energy change?

For a given spring, its total energy depends on the maximum elongation of the spring, e = KX ^ 2 / 2, and has nothing to do with the mass step vibration frequency of the oscillator. Therefore, if the amplitude is doubled, the total energy will be four times of the original

The displacement in simple harmonic motion is positive,

Of course
Displacement is a vector with positive and negative elements
In any motion, displacement has positive and negative effects
The positive direction is artificially specified, so the displacement is positive, that is, it is in the same direction as the specified direction, otherwise, it is negative, and it is opposite to the specified direction

When the aircraft taxis on the runway, the taxiing time is 16.2 seconds and the taxiing distance is 1200 meters

1 / 2 * a * t * t = s, directly bring in t = 16.2, s = 1200, directly find out how much a is equal to! I don't have an engineering calculator, it's hard to calculate!

When an object moves in a straight line with constant speed, the time to pass a certain distance x is T1, and the time to pass the next distance x is T2. What is the acceleration of the object

Through the first distance, the average speed is x / T1, the second X / T2 time interval is T2 / 2 + T1 / 2, and the acceleration is equal to the speed difference divided by the time a = (x / t2-x / T1) / (T2 / 2 + T1 / 2) 2 * x * (T1 - T2) = --- --- (T1 + T2) * T1 * T2

When the speed is equal to half of the landing speed, the falling distance is ()
A. H2B. H4C. H8D. H16

Let v be the velocity of an object landing on the ground. From V 2-V 02 = 2gx, V 2-0 = 2GH & nbsp; & nbsp; ① (V 2) 2-0 = 2GH & nbsp; and from (1) 2, H = 14h