Which substance is a combination of different atoms?

A scientist designed a foam container to help keep frozen foods from melting. Which best explains how the foam works?

FrozenT [24]

I think the answer should be D.It reduces the amount of thermal energy that is transferred from outside to inside the container.

6 0

4 years ago

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It is epistemically possible that a completed physics might include which of the following propositions? O Souls and other spiri

ohaa [14]

Answer:

option D.

Explanation:

The correct answer is option D.

At present the knowledge of physics does not includes the study related to souls , other spiritual substance.

Physics does not give the answers of question like God created universe , matter is unreal, etc.

So, there might will be possibility that in future complete physics will give the answer of all these questions i.e. correct answer is All of the above.

3 0

3 years ago

. How does the area of a rectangle relate to the lengths of each side?

iragen [17]

Area is 2-dimensional which means it has a length and a width area is measured in square units such as square inches, square feet or square meters. To find the area of a rectangle multiply the length by the width.

3 0

3 years ago

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A 0.4-kg toy train car moving forward at 3 m/s collides with and sticks to a 0.8–kg toy car that is traveling in the opposite di

Gemiola [76]

Hey there!

Seems like you're looking for the size and direction to the final velocity of the two cars. To find it, you must solve it like this.

0.4 kg(3 m/s) + 0.8kg(–2 m/s) = 1.2 kg m/s -1.6 kg m/s = –0.4 kg m/s

–0.4 kg m/s = 1.2 kg(v) = (–0.4 kg m/s)/(1.2 kg) = v = –0.33 m/s

So, the cars are traveling at -0.33 m/s in the direction of the second car.

Hope this helps

Tobey

4 0

3 years ago

Two transverse waves travel along the same taut string. Wave 1 is described by y1(x, t) = A sin(kx - ωt), while wave 2 is descri

Vadim26 [7]

Answer:

6) Wave 1 travels in the positive x-direction, while wave 2 travels in the negative x-direction.

Explanation:

What matters is the part $kx \pm \omega t$ , the other parts of the equation don't affect time and space variations. We know that when the sign is - the wave propagates to the positive direction while when the sign is + the wave propagates to the negative direction, but here is an explanation of this:

For both cases, + and -, after a certain time $\delta t$ ( $\delta t >0$ ), the displacement y of the wave will be determined by the $kx\pm\omega (t+\delta t)$ term. For simplicity, if we imagine we are looking at the origin (x=0), this will be simply $\pm \omega (t+\delta t)$ .

To know which side, right or left of the origin, would go through the origin after a time $\delta t$ (and thus know the direction of propagation) we have to see how we can achieve that same displacement y not by a time variation but by a space variation $\delta x$ (we would be looking where in space is what we would have in the future in time). The term would be then $k(x+\delta x)\pm\omega t$ , which at the origin is $k \delta x \pm \omega t$ . This would mean that, when the original equation has $kx+\omega t$ , we must have that $\delta x>0$ for $k\delta x+\omega t$ to be equal to $kx+\omega\delta t$ , and when the original equation has $kx-\omega t$ , we must have that $\delta x$ for $k\delta x-\omega t$ to be equal to $kx-\omega \delta t$

Note that their values don't matter, although they are a very small variation (we have to be careful since all this is inside a sin function), what matters is if they are positive or negative and as such what is possible or not .

In conclusion, when $kx+\omega t$ , the part of the wave on the positive side ( $\delta x>0$ ) is the one that will go through the origin, so the wave is going in the negative direction, and viceversa.

4 0

3 years ago