Answer:
0.0000076 grams
Explanation:
We're given the half life of Tritium to be 12.3 years. In order to find out the amount of substabce remaining:
Let's first find how many 'half lives' are in 250 years.
Now what is half life? It means the time taken for a given quantity of an element to lose half it's mass.
So in 12.3 years we can find that The amount of 250 g of Tritium will be 250/2 = 125 g. In 24.6 years we'll have 125/2 = 62.5 g
So now we can devise a formula:
Where m is the remaining amount and n is th number of half lives in the time given.
Using this formula we can calculate:
Doing this calculation we get:
As we can see a very small value remains.
Kepler derived his three laws of planetary motion entirely from
observations of the planets and their motions in the sky.
Newton published his law of universal gravitation almost a hundred
years later. Using some calculus and some analytic geometry, which
any serious sophomore in an engineering college should be able to do,
it can be shown that IF Newton's law of gravitation is correct, then it MUST
lead to Kepler's laws. Gravity, as Newton described it, must make the planets
in their orbits behave exactly as they do.
This demonstration is a tremendous boost for the work of both Kepler
and Newton.
<span>The component most affected by the collisions is vertical. The ball's vertical will either decrease or increase due to the collision. If the velocity is high during the collsion the ball's vertical will likely be higher and if the ball's velocity is low the vertical will be as well.</span>
Answer:
4.5 metres
Explanation:
Using Hooke's Law (
)
We need to find the spring constant of the bungee cord with the given extension and force, we can do this by substituting in known values.
Now we have found the spring constant of the bungee cord, we can substitute it in for the a different force. As the cord is the same we can use the same spring constant.
Iron III ion is an iron ion with a +3 charge. If iron bonded with oxygen, it would form Fe2O3 which is rust. In this case, the oxidation number on Fe is +3 and it is -2 on oxygen. This would be called iron (III) oxide.
<span>The oxidation number of an ion times the number of the ions must equal zero when added together in a molecule with no charge. In this case, there are 2 iron molecules and each has a positive 3 charge. 2x3=6. There are three oxygen molecules each with a negative 2 charge. 3x-2=-6. 6+-6=0</span>
