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3 years ago

5

g A CD is spinning on a CD player. You open the CD player to change out the disk and notice that the CD comes to rest after 15 r

evolutions with a constant deceleration of 120 r a d s 2 . What was the initial angular speed of the CD

1 answer:

Umnica [9.8K]3 years ago

7 0

Answer:

$\omega_1=150rads/sec$

Explanation:

From the question we are told that:

Number of Revolution $N=15=30\pi$

Deceleration $d= -120 rads/2$

Generally the equation for initial angular speed $\omega_1$ is mathematically given by

$\omega_2^2=\omega_1^2 +2(d)(N)$

$0=\omega_1^2 +2(-120)(20 \pi)$

$\omega_1^2=7200 \pi$

$\omega_1=150rads/sec$

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During a football game, a receiver has just caught a pass and is standing still. Before he can move, a tackler, running at a vel

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133 kg

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4 years ago

A student lifts a basketball to a height of 6 feet and lets the ball drop to the ground. Which statement accurately compares the

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3 years ago

Read 2 more answers

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bonufazy [111]

Answer:

a) $V=759.8727\ ft^3$

b) $\dot V=1.403\times 10^{-3}\ ft^3.s^{-1}$

c) $t\approx29.541\ s$

Explanation:

Given:

diameter of hole in the tank, $d'=0.1\ in=\frac{1}{120}\ ft$

position of the hole form the tank bottom, $h' =7\ ft$

initial level of turpentine in the tank before the leakage, $h_i=17.3\ ft$

level of turpentine in the tank after the repair of leakage, $h_f=13\ ft$

diameter of the tank, $d=15\ ft$

density of turpentine oil, $\rho=55\ lbm.ft^3$

a)

Now, volume of turpentine spilled:

$V=A.(h_i-h_f)$

where:

$A=$ area of the cross section of the tank's volume

$V=\pi .\frac{d^2}{4} \times(h_i-h_f)$

$V=\pi\times\frac{15^2}{4} \times(17.3-13)$

$V=759.8727\ ft^3$

b)

When the tank was full the liquid level was highest:

so velocity form the height of the hole will be given as:

$v=\sqrt{2g.(h_i-h')}$

$v=\sqrt{2\times 32.12\times (17.3-7) }$

$v=25.722\ ft.s^{-1}$

<u>Now we have the flow rate of the spillage given by:</u>

$\dot V=(\pi.\frac{d'^2}{4}) \times v$

$\dot V=\pi\times \frac{(\frac{1}{120})^2 }{4} \times 25.722$

$\dot V=1.403\times 10^{-3}\ ft^3.s^{-1}$

c)

Total time the leak was active can be calculated as:

$t=\frac{V}{\dot V}$

$t=\frac{759.8727}{25.722}$

$t\approx29.541\ s$

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4 years ago

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Naily [24]

Answer:

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