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STALIN [3.7K]
3 years ago
9

A skater makes one revolution per second, f = w/(2p) = 1, with her arms and leg stretched (left). By lowering her leg and bringi

ng her arms close to her chest (right) she reduces her moment of inertia from I to I′ = 0.4I. How many revolutions per second, f′ = w¢/(2p), is she making now? Show all your work.
Physics
2 answers:
mihalych1998 [28]3 years ago
8 0

Answer:

f'=w'/2p=2.49rev/s

Explanation:

The angular momentum L must be equal for both cases.

Hence you have that

L before = L after

L=I\omega

\omega=2\pi f

I = moment of inertia

w =angular momentum

Hence

L=L'\\I\omega =I'\omega'\\\omega'=\frac{I\omega}{I'}=\frac{I*2\pi *1}{0.4I}=15.70\frac{rad}{s}

f'=w'/2p=2.49rev/s

hope this helps!!

Firlakuza [10]3 years ago
4 0

Answer:

Answer is given in the attachment.

Explanation:

Download pdf
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Answer:

D.vibrations that cause changes in air pressure

Explanation:

Sound is a type of wave.

A wave is a periodic disturbance/oscillation that trasmits energy without transmitting matter. There are two different types of waves:

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- Longitudinal waves: in a longitudinal wave, the direction of the oscillation is parallel to the direction of motion of the wave. These waves are characterized by the presence of compressions (regions where the density of particle is higher) and rarefactions (regions where the density of particle is lower). Examples of longitudinal waves are sound waves.

Sound waves, in particular, consist of vibrations of the particles in a medium - most commonly, air - that occur back and forth along the direction of motion of the wave. Because of these motion, the air will have areas of higher pressure (which correspond to the compressions), where the density of particles is higher, and areas of lower pressure (which correspond to the rarefactions), where density of particles is lower.

3 0
3 years ago
Read 2 more answers
A printer is connected to a 1.0 m cable. if the magnetic force is 9.1 × x10-5 n, and the magnetic field is 1.3 × 10-4 t, what is
Valentin [98]
The magnetic force on a current-carrying wire due to a magnetic field is given by
F=ILB
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In our problem, L=1.0 m, F=9.1 \cdot 10^{-5} N and B=1.3 \cdot 10^{-4}T, so we can re-arrange the formula to find the current in the wire:
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3 years ago
You have given a power supply, copper wire, and an iron nail. What should you do to decrease the strength of the electro magnet?
Shkiper50 [21]
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A rectangular conducting loop of wire is approximately half-way into a magnetic field B (out of the page) and is free to move. S
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8 0
2 years ago
M=3000km v=25m/s what’s the momentum
valina [46]
<h3>Answer:</h3>

Momentum of the given body will be : 75000 Kg m/s

<h3>Explanation:</h3>

According to Newton's first law of motion, all bodies continue to be in the state of rest or motion unless an external force is applied on the body. We can use this in the case of momentum also

The formula of momentum is given by :

:\implies \sf\quad \sf \:  P = mv

Here, we are given the mass of the body ( m ) as 3000kg and the velocity of the body ( v ) as 25 m/s. On putting the values in the formula:

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8 0
2 years ago
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