The question is incomplete, here is the complete question:
The half-life of a certain radioactive substance is 46 days. There are 12.6 g present initially.
When will there be less than 1 g remaining?
<u>Answer:</u> The time required for a radioactive substance to remain less than 1 gram is 168.27 days.
<u>Step-by-step explanation:</u>
All radioactive decay processes follow first order reaction.
To calculate the rate constant by given half life of the reaction, we use the equation:
where,
= half life period of the reaction = 46 days
k = rate constant = ?
Putting values in above equation, we get:
The formula used to calculate the time period for a first order reaction follows:
where,
k = rate constant = 
t = time period = ? days
a = initial concentration of the reactant = 12.6 g
a - x = concentration of reactant left after time 't' = 1 g
Putting values in above equation, we get:
Hence, the time required for a radioactive substance to remain less than 1 gram is 168.27 days.
Answer:
You will put 1220.83ft³ of water in the pool
Step-by-step explanation:
radius = half of diameter
d = 18ft
r = 18ft / 2 = 9ft
To calculate the volume of a cylinder we have to use the following formula:
v = volume
h = height = 6ft
π = 3.14
r = radius = 9ft
v = (π * r²) * h
we replace with the known values
v = (3.14 * (9ft)²) * 6ft
v = (3.14 * 81ft²) * 6ft
v = 254.34ft² * 6ft
v = 1526.04ft³
The volume of the cylinder is 1526.04ft³
If it is filled to 80% then we have to multiply the volume by 80/100
1526.04ft³ * 80/100 = 1220.83ft³
You will put 1220.83ft³ of water in the pool
4x = 5x - 12
First you want to subtract 5x from both sides:
5x will cancel out
4x - 5 = -1
Next you want to divide -1 on both sides:
-1 will cancel out
-12/-1 = 12
Since there are two negatives it turns into a positive.
So your answer is x = 12.
Hope this Helps!!
Answer:
3
Step-by-step explanation:
52.1 x 26.4 to find the total area equals 1375.44
1375.44 / 500 = 2.75088
since you can’t buy parts you round tot he next whole number making the answer 3
The area of number four, the hexagon, is 841.78.
Hope this helps!
