if the velocity of the car reduces from 70km/h to 50km/h then the speed of the car will be equal to the speed of the lorry...
thus the relative velocity will be 0
They expend more oxygen. Littler endotherms lose warmth to the earth proportionately speedier than huge endotherms: less warm mass, protecting layers in littler creatures are less successful by dint of being more slender, and more prominent surface region to volume proportion implies snappier radiation of warmth
<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.