Answer:
81π
Step-by-step explanation:
-The sum of central angles in a circle add up to 360°.
-Let x be the area of the circle.
-Given the area of a 120° is 27π, the circles area can be calculated as:
Hence, the area of the circle is 81π
In a region where 48% of the population is male, there are 11 boys and 14 girls in a sample of children. What is p and ^p for ma
1 answer:
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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.