All categories

2 years ago

The __________muscle raises the eyebrows and causes wrinkles across the forehead.

1 answer:

7 0

Horizontal forehead wrinkles are caused by contraction of the frontalis muscles. The frontalis muscles are two large fanlike muscles that extend from the eyebrow region to the top of the forehead. I think this is the answer

You might be interested in

A ray of light crosses a boundary between two transparent materials. The medium the ray enters has a larger optical density. Whi

Tpy6a [65]

Answer:

The wavelength of the light decreases as it enters into the medium with the greater optical density.

The frequency of the light remains constant as it transitions between materials.

Explanation:

- When a ray of light crosses a boundary between two different materials, it undergoes refraction: the ray changes direction, and it also changes speed, according to the relationship:

$v=\frac{c}{n}$

where v is the speed of the ray of light in the material, c is the speed of light in a vacuum, n is the index of refraction of the material, which is larger for a medium with larger optical density. So, from the equation, we see that the larger the optical density, the smaller the speed of the wave.

- The frequency of the light does not depend on the properties of the medium, so it remains unchanged: therefore the statement

The frequency of the light remains constant as it transitions between materials.

is correct.

- Moreover, the wavelength of the ray of light is related to the speed and the frequency by the equation

$\lambda=\frac{v}{f}$

where v is the speed and f the frequency. Since we have seen that v decreases and f remains constant, this means that the wavelength decreases as well, so the statement

The wavelength of the light decreases as it enters into the medium with the greater optical density.

is also correct.

5 0

2 years ago

2 ways to change frictional force between 2 objects

Zanzabum

In order to change the frictional force between two solid surfaces, it can be changed by shorter distances and by the amount of weight it has or the amount of force that is pushing that object to go however distance it can.

5 0

2 years ago

Read 2 more answers

A car of mass 998 kilograms moving in the positive y–axis at a speed of

aksik [14]

The total momentum should come out to be 2.0 x 10^4 kilogram meters/second

8 0

2 years ago

Read 2 more answers

An ant is crawling along a yardstick that is pointed with the 0-inch mark to the east and the 36-inch mark to the west. It start

galina1969 [7]

Answer:

it moves 25 inches.

Explanation:

the east west bit isn't important, ignore it. if an ant starts at 6 then moves to 19 then we need to subtract 19 from 6, that's 13. then it moves to 7. the difference between 19 and 7 is 12. add that to 13 and you get 25. it's important to remember that there is no such thing as negative distance. if it moved, then it counts.

3 0

2 years ago

Give examples of not useful high friction

Tatiana [17]

Friction can be bad by being too strong or too weak.

Sometimes, when it is too strong, it decreases efficiency since some energy is wasted and turns to heat. Friction can also damage equipment/objects like when you slide it on the floor.

When friction is too weak, like for instance when there is black ice- our center of gravity is displaced too quickly and we can fall. Likewise, if there is a lot of slush on the ground, cars can slip and slide.

6 0

3 years ago