10. A safe place to use the trebuchet would be away from other buildings and people. A good example of a place would be a large field with no nearby structures.
14. Many factors need to be kept consistent throughout the experiment. One example of a variable that would need to be consistent is the weight and size of the projectile.
15. It is important to do many trials so that you can make sure that the results of each trial are nearly the same. If they are all vastly different, then it means that something has gone wrong.
Sorry I was only able to answer a few questions, but I hope these few answers help! :)
Answer:
The transmitted intensity through all polarizers is 
Explanation:
According to Malu's law the intensity of a polarized light having an initial intensity
is mathematically represented as

Now considering the polarizer(The polarizing disk) the equation above becomes

Where n is the number of polarizers
Substituting
for the initial intensity 3 for the n and 20° for the angle of rotation


Pitch is related to frequency
Answer:
C.Supersaturated
Explanation:
There are three types of solution:
<u>SATURATED SOLUTION</u>:
It is the solution that contains maximum amount of solute dissolved in a solution in normal conditions.
<u>UNSATURATED SOLUTION</u>:
It is the solution that contains less than the maximum amount of solute dissolved in a solution in normal conditions. It has space for more solute to be dissolved in it.
<u>SUPERSATURATED SOLUTION:</u>
It contains more than the maximum amount of solute dissolved in it. Such a solution has no capacity to dissolve any more solute under any conditions.
Since the sugar is no more dissolving in the tea and has settled down. Therefore, the solution is:
<u>C.Supersaturated</u>