Answer:
The decided by staring at and observing the stars.
Explanation:
1. The signs of the velocities of the balls were changed, this is a result of the elastic collision between the two balls. The law involved in here is the Law of Interaction.
2. During the elastic collision, the momentum is conserved.
3. The velocity would be lower. There is a tendency for these balls to stick together.
Answer:
The archerfish must spit at a minimum speed of 
at an angle of 
above the horizontal.
Explanation:
Hi
First of all, we need to find the angle above the horizontal at which the archerfish must spit, as we can see in the attachment this angle is 
.
Then we use the formula 
, as we clear it for 
, we obtain, 
, therefore the archerfish must spit at a minimum speed of at an angle of above the horizontal.
<h2>
Answer: True </h2><h2>
</h2>
Each atom emits or absors electromagnetic radiation, but only in some frequencies that are characteristic of its chemical element.
Now, if we supply energy in the form of heat (thermal energy) to a certain element in its gas phase, this will be stimulated and its atoms will emit radiation in certain frequencies of the visible spectrum, which constitute its <u>emission spectrum</u>.
If the same element, also in gaseous state, receives electromagnetic radiation, it absorbs in certain frequencies of the visible spectrum, <u>precisely the same ones in which it emits when it is stimulated by heat</u>. This will be its <u>absorption spectrum.</u>
<h2>
This means that every element absorbs radiation in the same wavelengths in which it emits it. </h2>
