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Mice21 [21]
4 years ago
11

When it is at rotating at full speed, a disk drive in a certain old computer game system revolves once every 0.050 seconds. Star

ting from rest, it takes two revolutions for the disk to reach full speed. Assuming that the angular acceleration of the disk is constant, what is its angular acceleration while it is speeding up
Physics
1 answer:
Gemiola [76]4 years ago
3 0

Answer:

α = 200*π rad/sec²

Explanation:

  • If the disk drive revolves once every 0.05 sec, this means that the angular velocity can be expressed as follows:

        \omega = \frac{2*\pi}{0.05s} = 40*\pi rad/sec

  • (just applying the definition of angular velocity)
  • Now, it the disk started from rest, and took two revolutions to reach to full speed, assuming that the angular acceleration is constant, we can find the angular acceleration applying this kinematic equation:

        \omega_{f} ^{2} -\omega_{0} ^{2} = 2*\alpha * \Delta\theta

  • where Δθ, is the angle rotated while it went from rest to full speed, i.e., 2 revolutions, or 2*π rads.
  • Replacing by the value that we found for ωf (as ω₀ = 0), we  can solve for α :

       \alpha =\frac{\omega_{f}^{2} }{2*\Delta\theta} = \frac{(40*\pi)^{2} }{2*2*2*\pi } =\\ \\ \alpha = 200*\pi rad/sec2

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Lelu [443]

Answer:

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8 0
3 years ago
A point charge Q is held at a distance r from the center of a dipole that consists of two charges ±q separated by a distance s.
marishachu [46]

Answer:

a) the magnitude of the force is

F= Q(\frac{kqs}{r^3}) and where k = 1/4πε₀

F = Qqs/4πε₀r³

b)  the magnitude of the torque on the dipole

τ = Qqs/4πε₀r²

Explanation:

from coulomb's law

E = \frac{kq}{r^{2} }

where k = 1/4πε₀

the expression of the electric field due to dipole at a distance r is

E(r) = \frac{kp}{r^{3} } , where p = q × s

E(r) = \frac{kqs}{r^{3} } where r>>s

a) find the magnitude of force due to the dipole

F=QE

F= Q(\frac{kqs}{r^3})

where k = 1/4πε₀

F = Qqs/4πε₀r³

b) b) magnitude of the torque(τ) on the dipole is dependent on the perpendicular forces

τ = F sinθ × s

θ = 90°

note: sin90° = 1

τ = F × r

recall  F = Qqs/4πε₀r³

∴ τ = (Qqs/4πε₀r³) × r

τ = Qqs/4πε₀r²

8 0
3 years ago
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ivanzaharov [21]
I believe the answer would be zero because the q1 and q2 are equal on opposite sides and it

hope this helps
3 0
3 years ago
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