Simplicity of conducting the study is to archival research; as ability to test large numbers participants is to survey.
Because dogs have their bodies covered with fur, sweating is less effective. Dogs have sweat glads in places where there is little fur. However this is not enough in some hot days. To keep the body temperature in order dogs have to rely on panting. The interior of mouth and lungs is wet, so breathing quickly speeds up cooling. It acts similarly to wind blowing on sweaty person's skin.
You can try it on your own. When you breathe heavily you will feel coolness :)
In order to evaporate (change state from liquid to gas) heat energy has to be delivered to water. The heat energy is taken from the body of dog, thus cooling it.
<h2>
Answer: The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.</h2>
Explanation:
The half-life of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this case, we are given the half life of two elements:
beryllium-13:
beryllium-15:
As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?
We can find it out by the following expression:
Where is the amount we want to find:
Finally:
Therefore:
The half-life of beryllium-15 is <u>400 times greater than</u> the half-life of beryllium-13.
Missing detail in the text:
"<span>A small glass bead has been charged to + 25 nC "
Solution
The force exerted on a charge q by an electric field E is given by
</span>
<span>Considering the charge on the bead as a single point charge, the electric field generated by it is
</span>
with
,
is the charge on the bead. We want to calculate the field at
:
The proton has a charge of
, therefore the force exerted on it is
And finally, we can use Newton's second law to calculate the acceleration of the proton. Given the proton mass,
, we have
The charge on the bead is positive, and the proton charge is positive as well, therefore the proton is pushed away from the bead, so: