All categories

2 years ago

I have multiple questions!

Physics

1 answer:

UNO [17]2 years ago

3 0

I'm not sure about the rest but for question 2:

A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.

You might be interested in

A copper block rests 30.0 cm from the center of a steel turntable. The coefficient of static friction between the block and the

PIT_PIT [208]

Answer:

refer to the above attachment

3 0

1 year ago

Qué ocurre con el espectro cuando se interpone el celofán de colores?

Travka [436]

Answer: You will only see the color that cellophane lets through

Explanation:

Let's begin by the fact the whole electromagnetic spectrum is known as "white light", which is composed by a range of colors (wavelengths).

Now, if we have a source with white light (the Sun, for example) and we interpose a cellophane of any color (let's choose red), this cellophane will act as a filter and will only let pass the color of the cellophane.

This is because the filter will absorb the other colors of the spectrum.

3 0

2 years ago

An environmental scientist gives a demonstration on composting. Roger is in the audience. He wonders how composting discarded fo

Wittaler [7]

Answer:

Explanation:

I just did the test

4 0

3 years ago

Two double bonds means that the total number of electrons being shared in the molecule is

torisob [31]

One double bond consists 4 electrons, so 2 double bonds means 8 electrons

7 0

3 years ago

A fluid flows along the x axis with a velocity given by V = ( x / t ) ˆ i , where x is in feet and t in seconds. (a) Plot the sp

umka21 [38]

Answer:

V_local = -x/t^2

V_convec = x/t^2

a = V_local + V_convec = 0

e) When a particle moves towards postive x direction its convective velocity increases, but at the same time the local velocity deacreases (at the same rate) when time increases

Explanation:

Hi!

You can see plots for a) and b) attached on this document

The local acceleration is just teh aprtial derivative of the velocity with respect to t:

$\frac{dV}{dt} = \frac{d}{dt} \frac{x}{t}=- \frac{x}{t^2}$

And the convective acceleration is given by the product of the velocity times the gradient of the velocity, that is:

$\vec{v} \cdot \nabla \vec{v} = v ( \frac{dv}{dx} ) =\frac{x}{t} \frac{1}{t} = \frac{x}{t^2}$

Since the acceleration of any fluid particle is the sum of the local and convective accelerations, we can easily see that it is equal to zero, since they are equal but with opposit sign

This is because of teh particular form of the velocity. A particle will move towards areas of higher velocities (convectice acceleration), but as time increases, the velocity is also decreasing (local acceleration), and the sum of these quantities adds up to zero

3 0

3 years ago