Which of the following elements is a metalloid?

Why is it important to have a balanced centrifuge?

ratelena [41]

It is important to properly balance a centrifuge because an unbalanced machine can damage the rotor, cause catastrophic damage to the machine itself, or even injure or kill lab personnel working in the room. Balancing a centrifuge involves spreading the weight of the samples across the entire rotor.

8 0

4 years ago

NEED HELP ASAP<br> thanks + BRAINLIST only for correct answer

Fantom [35]

Answer:

I. They come from sources across space

II. They travel in a straight line from their source.

III. They can be reflected by some types of material.

Explanation:

Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.

The following statements about light waves are true;

I. They come from sources across space.

II. They travel in a straight line from their source.

III. They can be reflected by some types of material. reflection occurs when a ray of light or wavefronts bounces off a smooth surface. Thus, when light hit a surface, it bounces back to the medium from which it was originally propagated with.

However, light waves cannot travel through all type of material except materials that are transparent or translucent but not opaque.

4 0

3 years ago

What is the (magnitude of the) centripetal acceleration (as a multiple of g=9.8~\mathrm{m/s^2}g=9.8 m/s 2 ) towards the Eart

Wittaler [7]

Answer:

The centripetal acceleration as a multiple of $g=9.8 m/s^{2}$ is $1.020x10^{-3}m/s^{2}$

Explanation:

The centripetal acceleration is defined as:

$a = \frac{v^{2}}{r}$ (1)

Where v is the velocity and r is the radius

Since the person is standing in the Earth surfaces, their velocity will be the same of the Earth. That one can be determined by means of the orbital velocity:

$v = \frac{2 \pi r}{T}$ (2)

Where r is the radius and T is the period.

For this case the person is standing at a latitude $71.9^{\circ}$ . Remember that the latitude is given from the equator. The configuration of this system is shown in the image below.

It is necessary to use the radius at the latitude given. That radius can be found by means of trigonometric.

$\cos \theta = \frac{adjacent}{hypotenuse}$

$\cos \theta = \frac{r_{71.9^{\circ}}}{r_{e}}$ (3)

Where $r_{71.9^{\circ}}$ is the radius at the latitude of $71.9^{\circ}$ and $r_{e}$ is the radius at the equator ( $6.37x10^{6}m$ ).

$r_{71.9^{\circ}}$ can be isolated from equation 3:

$r_{71.9^{\circ}} = r_{e} \cos \theta$ (4)

$r_{71.9^{\circ}} = (6.37x10^{6}m) \cos (71.9^{\circ})$

$r_{71.9^{\circ}} = 1.97x10^{6} m$

Then, equation 2 can be used

$v = \frac{2 \pi (1.97x10^{6} m)}{24h}$

Notice that the period is the time that the Earth takes to give a complete revolution (24 hours), this period will be expressed in seconds for a better representation of the velocity.

$T = 24h . \frac{3600s}{1h}$ ⇒ $84600s$

$v = \frac{2 \pi (1.97x10^{6} m)}{84600s}$

$v = 146.31m/s$

Finally, equation 1 can be used:

$a = \frac{(146.31m/s)^{2}}{(1.97x10^{6}m)}$

$a = 0.010m/s^{2}$

Hence, the centripetal acceleration is $0.010m/s^{2}$

To given the centripetal acceleration as a multiple of $g=9.8 m/s^{2}$ it is gotten:

$\frac{0.010m/s^{2}}{9.8 m/s^{2}} = 1.020x10^{-3}m/s^{2}$

6 0

3 years ago

Which best explains how Selena can correct her error? She can change the magnets so like poles are facing each other. She can ch

alexandr402 [8]

Complete question is;

Selena drew a diagram to show how current moves in a loop of wire that is placed between two magnets. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire with green arrows at its ends away from the magnets pointing away from the magnets. Red arrows point from N to S. Which best explains how Selena can correct her error?

A) She can change the magnets so like poles are facing each other.

B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.

C) She can change the arrows so they show the magnetic field reversing direction between the magnets.

D) She can change the magnetic poles so they are both on one side of the loop.

Answer:

B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.

Explanation:

Since the direction of the arrows point north and south whereas the magnets are east and west, it means the arrows are not pointing in the correct direction. To correct it she will have to make sure the arrows are pointing in opposite directions of the magnet via the sides of the loop.

7 0

3 years ago

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With a force of 5 Newton's Amanda pushes the stacks of books to the right. At the same time Jeremih her little brother pushes th

Fynjy0 [20]

Alright, so solving for the net force is a rather simple and easy step. I want to briefly explain how you determine the net force, but before I do, let's examine the problem together. What has been provided to us? What direction is it going? Well, we can look at the information!

Amanda's Force: 5 N

Jeremiah's Force: 10 N

They're both pushing on the books, but in different directions. Left and right. If Amanda is pushing the books to the right 5 newtons, and Jeremiah is pushing the books to the left with 10 newtons, that means the net force is 5. The book is being pushed to the left! We can say that because Jeremiah's force is much larger than his sisters.

We can determine the net force from the following;

Net Force → 10 N - 5 N = 5 N

In conclusion, your answer should be a total of five (5) newtons

4 0

3 years ago

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