Second, in uniform circular motion, the speed is constant, but the direction of the speed is always changing, so there is acceleration, that is, the acceleration is not zero.
Thirdly, the acceleration corresponding to uniform circular motion is called centripetal acceleration, and the direction points to the center of the circle.
Extended data:
First, the physical meaning of acceleration
A physical quantity indicating the speed of change of particle velocity.
For example, when two cars start to stop, they accelerate to a speed of 10m/s at a uniform speed, a car needs 10s, and a car needs 5s ... Their speed changes from 0 to 10 m/s, and the speed changes10m/s..
So their speed changes are the same. But obviously, car B changes faster. We use acceleration to describe this phenomenon: the acceleration of car B (a = Δ V/Δ T, where Δ V is the speed change) > the acceleration of car A..
Obviously, under the condition of the same speed change, the acceleration of car B with less time consumption is greater. That is to say, the starting performance of car B is better than that of car A, so the acceleration is a physical quantity indicating the change of the speed of the object.
Second, the unit
M/s or m/s (m/s 2)
Acceleration is a vector with both magnitude and direction. (Directions are indicated by+and-)
The magnitude of acceleration is equal to the change of speed in unit time; The direction of acceleration is always the same as the direction of speed change Δ v, especially in linear motion, if the direction of acceleration is the same as the speed, the speed will increase; The acceleration direction is opposite to the speed, and the speed decreases.
Acceleration is equal to the first derivative of velocity time and the second derivative of displacement time.
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Baidu encyclopedia-uniform circular motion