If the speed of a motor is 1200R / min, the rotation period is_ s. The angular velocity is_ Rad / s, the radius from point a to the center of the circle is 0.5m, then the line of point a The speed is____ m/s

Rotational speed φ = 1200R / min = 1200 / 60 R / S = 20 R / S
Period T = 1 / F = 1 / 20 s = 0.05 s
Angular velocity ω = 2 * π * φ = 40 π rad / S
Linear velocity v = R * ω = 0.5 * 40 * π = 20 π M / S
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