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A child is pushing a merry-go-round. The angle through which the merry-go-round has turned varies with time according to θ(t)=γt+βt3, where γ= 0.422 rad/sand β= 1.00×10^−2 rad/s3.

Part A
Calculate the angular velocity of the merry-go-round as a function of time.
Express your answer in terms of the variables β, γ, and t.
Part B
What is the initial value of the angular velocity?
Part C
Calculate the instantaneous value of the angular velocity ωz at t= 5.35 s .
Part D
Calculate the average angular velocity ωav−z for the time interval t=0 to t= 5.35 s .

User Mrousavy
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1 Answer

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Answer:

.

Part A

Calculate the angular velocity of the merry-go-round as a function of time.

Express your answer in terms of the variables β, γ, and t.

Part B

What is the initial value of the angular velocity?

Part C

Calculate the instantaneous value of the angular velocity ωz at t= 5.35 s .

Part D

Calculate the average angular velocity ωav−z for the time interval t=0 to t= 5.35 s .

Part A:

Angular velocity is the rate of change of the angle, so we can calculate it by taking the derivative of θ(t) with respect to time:

ω(t) = dθ(t)/dt = γ + 3βt^2

Therefore, the angular velocity of the merry-go-round as a function of time is given by:

ω(t) = γ + 3βt^2

Part B:

The initial value of the angular velocity is the angular velocity at t=0. Plugging in t=0 into the equation above, we get:

ω(0) = γ + 3β(0)^2 = γ

So the initial value of the angular velocity is simply γ.

Part C:

To find the instantaneous value of the angular velocity at t=5.35 s, we can plug in t=5.35 into the equation we found in part A:

ω(5.35) = γ + 3β(5.35)^2 = 0.422 + 3(1.00×10^−2)(5.35)^2 ≈ 1.05 rad/s

Therefore, the instantaneous value of the angular velocity at t=5.35 s is approximately 1.05 rad/s.

Part D:

The average angular velocity ωav−z for the time interval t=0 to t=5.35 s is given by the change in the angle divided by the time interval:

ωav−z = [θ(5.35) - θ(0)]/(5.35 - 0)

Plugging in the values we are given, we get:

ωav−z = [γ(5.35) + β(5.35)^3/3 - γ(0) - β(0)^3/3]/5.35

ωav−z = [γ(5.35) + β(5.35)^3/3]/5.35

ωav−z ≈ 0.667 γ + 0.101 β

Therefore, the average angular velocity ωav−z for the time interval t=0 to t=5.35 s is approximately 0.667 times the value of γ plus 0.101 times the value of β.

User Hands
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