1. ________________electricity is the type of electricity commonly used in homes and businesses throughout the world.

3N<br> 3 N<br> What is the net force of the box?

zepelin [54]

6N I think I’m pretty sure

3 0

3 years ago

A student sits on a rotating stool holding two 3.09-kg masses. When his arms are extended horizontally, the masses are 1.08 m fr

schepotkina [342]

Answer:

a

The New angular speed is $w_f = 2.034 rad/s$

b

The Kinetic energy before the masses are pulled in is $KE_i = 3.101 \ J$

c

The Kinetic energy after the masses are pulled in is $KE_f = 8.192 \ J$

Explanation:

From the we are told that masses are 1.08 m from the axis of rotation, this means that

The radius $r =1.08m$

The mass is $m = 3.09\ kg$

The angular speed $w = 0.770 \ rad/sec$

The moment of inertia of the system excluding the two mass $I = 3.25 \ kg \cdot m^2$

New radius $r_{new} = 0.34m$

Generally the conservation of angular momentum can be mathematical represented as

$w_f = [\frac{I_i}{I_f} ]w_i .....(1)$

Where $w_f$ is the final angular speed

$w_i$ is the initial angular speed

$I_i$ is the initial moment of inertia

$I_f$ is the final moment of inertia

Moment of inertia is mathematically represented as

$I = m r^2$

Where I is the moment of inertia

m is the mass

r is the radius

So the Initial moment of inertia is given as

$I_i = moment \ of \ inertia \ of\ the \ two \ mass \ + 3.25 \ kg \cdot m^2$

$I_i = 2m r^2 + 3.25$

The multiplication by is because we are considering two masses

$I_i = 2 [(3.09)(1.08)^2] +3.25 = 10.46 kg \cdot m^2$

So the final moment of inertia is given as

$I_f = 2[(3.09)(0.34)^2] +3.25 = 3.96 \ kg \cdot m^2$

Substituting these values into equation 1

$w_f = [\frac{10.46}{3.96} ] * 0.77 = 2.034 \ rad/sec$

Generally Kinetic energy is mathematically represented in term of moment of inertia as

$KE = \frac{1}{2} * I * w^2$

Now considering the kinetic energy before the masses are pulled in,

$KE_i = \frac{1}{2} * I_i * w^2_i$

The Moment of inertia would be $I_i = 10.46 \ Kg \cdot m^2$

The Angular speed would be $w_i = 0.77 \ rad/s$

Now substituting these value into the equation above

$KE_i = \frac{1}{2} * (10.46) * (0.770)^2 = 3.101 J$

Now considering the kinetic energy after the masses are pulled in,

$KE_f = \frac{1}{2} * I_f * w^2_f$

The Moment of inertia would be $I_f = 3.96 \ Kg \cdot m^2$

The Angular speed would be $w_f = 2.034 \ rad/s$

Now substituting these value into the equation above

$KE_f= \frac{1}{2} *(3.96)(2.034)^2$

$= 8.192J$

8 0

3 years ago

A car engine has power than a horse because a car engine does the same amount of work in time. Yasmin and Raj each had 10 boxes

labwork [276]

Answer:

A car engine has more power than a horse because a car engine does the same amount of work in time. Yasmin and Raj each had 10 boxes of equal weight to stack next to each other on the same shelf, at the same height and in the same arrangement. Yasmin completed the task in 2 minutes, while Raj took 3 minutes to stack his boxes. Raj applied less power than Yasmin because his stacking took more time to do the same amount of work.

Explanation:

4 0

2 years ago

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Two linear polarizing filters are placed one behind the other so that their transmission directions form an angle of 45 ° . A be

makvit [3.9K]

The transmitted intensity will be the quarter of the incident intensity of light, (I = 0.25 I₀), when two linear polarizing filters are placed one behind the other forming the angle of 45°.

<u>Explanation:</u>

Polarizers are used for constraining the direction of propagation of light waves. So depending upon the angle of polarizer, the transmitted rays will follow that angle only and the remaining lights waves at different angles will be reflected back. So basically it works like a filter or optical filters.

So, the transmitted intensity will be less compared to the original intensity of light as the beam will get confined in a particular angle.

The relation between transmitted intensity and incident intensity is given by Malus's law.

$I = { \frac {I_{0}} {2}} \times cos^{2} \alpha$

Here, I is the transmitted intensity, I₀ is the incident intensity and α is the angle of the polarizer.

In the present case, two polarizers are used with same angle, so the first one termed as polarizer, while the second one will be termed as analyzer. The angle which is used to polarize the intensity of the incident beam is the angle of 45°.

Then, according to Malus's law,

I = I₀ cos² 45 = (I₀/2)×(1/√2)² = I₀/4 = $0.25\ I_0$

So, the transmitted intensity will be the quarter of the incident intensity of light, (I = 0.25 I₀), when two linear polarizing filters are placed one behind the other forming the angle of 45°.

6 0

2 years ago

In an observational study researchers try not too ?

jok3333 [9.3K]

They try not to interfere or play any part j what happens rather they just look at it and see the results

5 0

2 years ago

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