Answer:If an object's speed changes, or if it changes the direction it's moving in,
then there must be forces acting on it. There is no other way for any of
these things to happen.
Once in a while, there may be a group of forces (two or more) acting on
an object, and the group of forces may turn out to be "balanced". When
that happens, the object's speed will remain constant, and ... if the speed
is not zero ... it will continue moving in a straight line. In that case, it's not
possible to tell by looking at it whether there are any forces acting on it
<h2>
Answer: Heat transfer by radiation</h2>
Explanation:
There are three ways in which the thermal transfer (heat) occurs:
1. By Conduction, when the transmission is by the <u>direct contact.</u>
2. By Convection, heat transfer<u> in fluids</u> (like water or the air, for example).
3. By <u>Radiation</u>, by the electromagnetic waves (they can travel through any medium and in vacumm or empty space)
Since outter space is vacuum (sometimes called "empty"), energy cannot be transmitted by convection, nor conduction. It must be transmitted by electromagnetic waves that are able to travel with or without a medium.
Answer:
By observing the color of lines in the spectrum.
Explanation:
There are two types of lines in the spectrum explained below:
i) Bright lines: Bright lines occurs on the spectrum when atoms emit photons. These bright lines show the emission line spectrum.
ii) Dark Lines: Dark lines occurs on the spectrum when atoms absorb photons. These black lines show the absorption line spectrum.
Hence, by observing the color of lines it is possible to identify emission line spectrum and absorption line spectrum.
The answer is going to be 40