Answer:
- <u>59.0891 g (rounded to 4 decimal places)</u>
Explanation:
<em>Half-life time</em> of a radioactive substance is the time for half of the substance to decay.
Thus, the amount of the radioactive substance that remains after a number n of half-lives is given by:
Where:
- A is the amount that remains of the substance after n half-lives have elapses, and
- A₀ is the starting amount of the substance.
In this problem, you have that the half-live for your sample (polonium-210) is 138 days and the number of days elapsed is 330 days. Thus, the number of half-lives elapsed is:
- 330 days / 138 days = 2.3913
Therefore, the amount of polonium-210 that will be left in 330 days is:
Answer:
r = 5y/8
Step-by-step explanation:
isolate the variable by dividing each side by factors that contain the variable.
Answer:
The width of the scale model is 33 inches.
Step-by-step explanation:
This question is solved making a relation with the scale model.
In the scale, 3 inches are worth 11 real feet.
The actual width of the building is 121 feet, so we find it's scale by a rule of three.
3 inches - 11 feet
x inches - 121 feet

Simplifying by 3, both sides

The width of the scale model is 33 inches.