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An electric turntable 0.750 m in diameter is rotating about a fixed axis with an initial angular velocity of 0.250 rev/s and a constant angular acceleration of 0.900 rev/s^2. Compute the angular velocity of the turntable after 0.200s Through how many revolutions has the turntable spun in this time interval? What is the tangential speed of a point on the rim of the turntable at t = 0.200? What is the magnitude of the resultant acceleration of a point on the rim at t = 0.200s?

User Itsclarke
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Answer:

To solve this problem, we will use the kinematic equations of rotational motion:

1. ωf = ωi + αt (final angular velocity = initial angular velocity + angular acceleration x time)

2. θ = ωit + 1/2 αt^2 (angle rotated = initial angular velocity x time + 1/2 x angular acceleration x time^2)

3. vf = ri (final tangential velocity = radius x final angular velocity)

4. ar = rα (centripetal acceleration = radius x angular acceleration)

where ω is angular velocity, α is angular acceleration, t is time, θ is angle, v is tangential velocity, r is radius, and a is acceleration.

a) Using equation 1, we can find the final angular velocity:

ωf = ωi + αt

ωf = 0.250 rev/s + 0.900 rev/s^2 x 0.200 s

ωf = 0.430 rev/s

b) Using equation 2, we can find the angle rotated:

θ = ωit + 1/2 αt^2

θ = 0.250 rev/s x 0.200 s + 1/2 x 0.900 rev/s^2 x (0.200 s)^2

θ = 0.0350 rev

c) Using equation 3, we can find the tangential velocity at t = 0.200 s:

vf = ri

vf = (0.750 m/2) x 0.430 rev/s x 2π rad/rev

vf = 1.62 m/s

d) Using equation 4, we can find the centripetal acceleration at t = 0.200 s:

ar = rα

ar = 0.750 m/2 x 0.900 rev/s^2 x 2π rad/rev

ar = 2.12 m/s^2

The magnitude of the resultant acceleration of a point on the rim at t = 0.200 s is the vector sum of the tangential and centripetal accelerations:

a = √(at^2 + ar^2)

a = √(vf^2/r^2 + ar^2)

a = √((1.62 m/s)^2/(0.750 m/2)^2 + (2.12 m/s^2)^2)

a = 4.58 m/s^2

Therefore, the angular velocity of the turntable after 0.200 s is 0.430 rev/s, it has spun through an angle of 0.0350 rev, the tangential speed of a point on the rim of the turntable at t = 0.200 is 1.62 m/s, and the magnitude of the resultant acceleration of a point on the rim at t = 0.200 s is 4.58 m/s^2.

Step-by-step explanation:

User Slv
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