Can someone please help?

A skater extends her arms, holding a 2 kg mass in each hand. She is rotating about a vertical axis at a given rate. She brings h

Usimov [2.4K]

Explanation:

It is known that relation between torque and angular acceleration is as follows.

$\tau = I \times \alpha$

and, I = $\sum mr^{2}$

So, $I_{1} = 2 kg \times (1 m)^{2} + 2 kg \times (1 m)^{2}$

= 4 $kg m^{2}$

$\tau_{1} = 4 kg m^{2} \times \alpha_{1}$

$\tau_{2} = I_{2} \alpha_{2}$

So, $I_{2} = 2 kg \times (0.5 m)^{2} + 2 kg \times (0.5 m)^{2}$

= 1 $kg m^{2}$

as $\tau_{2} = I_{2} \alpha_{2}$

= $1 kg m^{2} \times \alpha_{2}$

Hence, $\tau_{1} = \tau_{2}$

$4 \alpha_{1} = \alpha_{2}$

$\alpha_{1} = \frac{1}{4} \alpha_{2}$

Thus, we can conclude that the new rotation is $\frac{1}{4}$ times that of the first rotation rate.

8 0

3 years ago

A box, compressing a spring by 4 m, is loaded and ready. Moments later the 8.0 kg box has been launched with

Mrac [35]

Answer:

50 N/m

Explanation:

Elastic energy = kinetic energy

EE = KE

½ kx² = ½ mv²

½ k (4 m)² = ½ (8.0 kg) (10.0 m/s)²

k = 50 N/m

3 0

3 years ago

In the macroscopic world, you know that you can hear but cannot see around corners. Under what conditions does light bend around

omeli [17]

Answer:

a much larger slit, the phenomenon of Sound diffraction that slits for light.

this is a series of equally spaced lines giving a diffraction envelope

Explanation:

The diffraction phenomenon is described by the expression

d sin θ = m λ

Where d is the distance of the slit, m the order of diffraction that is an integer and λ the wavelength.

For train the diffraction phenomenon, the d / Lam ratio is decisive if this relation of the gap separation in much greater than the wavelength does not reduce the diffraction phenomenon but the phenomena of geometric optics.

The wavelength range for visible light is 4 10⁻⁷ m to 7 10⁻⁷ m. The wavelength range for sound is 17 m to 1.7 10⁻² m. Therefore, with a much larger slit, the phenomenon of Sound diffraction that slits for light.

When we add a second slit we have the diffraction of each one separated by the distance between them, when the integrals are made we arrive at the result of the interference phenomenon, a this is a series of equally spaced lines giving a diffraction envelope

When I separate the distance between the two slits a lot, the time comes when we see two individual diffraction patterns

6 0

3 years ago

if the moon were somehow knocked out of orbit and flew off into outer space, what are the possible effects on the earth?

Anarel [89]

<h2>Answers:</h2>

<u>The possible effects on the earth will be</u><u> 1) No light during night 2) No tides</u>

<h2>Explanation:</h2>

As we know that tides are caused by the differential gravitational force on the equatorial regions by the moon. So if the Moon escapes from Earth, the main effect would be the lack of tides on Earth The region closer to the Moon experiences more gravitational force than the region on Earth away from the Moon. Other effects will be no more Moon to light up the night sky and no more solar eclipses.

5 0

3 years ago

While two forces act on it, a particle of mass m=3.2kg is it to move continuously with velocity (3m/s)i - (4m/s)j . one of the f

marta [7]

Mmm tricky.
Since the velocity is constant, I'm going to assume there is no acceleration in any direction. This means there is no net force in the I or J forection!

Since there are 2 forces, both must be equal and opposite in direction to perfectly cancel each other out.

So the opposite of F1 is (-2N)I + (6N)J!

8 0

3 years ago