There are 4 questions related to this problem:
1 If the half-life of the drug is 7.3 hours, what fraction of the drug remains in the patient after 24 hours?The amount of the drug is halved every 7.3-hour period, and 24 hours equals 24/7.3 of these halving periods.
So the portion of the drug left over after 24 hours is (1/2) ^ (24/7.3) = 0.10224 2 Write a general expression for the amount of the drug in the patient immediately after taking the nth dose of the drug
One method is to combine the residual amounts from each amount, when the nth dose arises; this will contain adding a finite geometric series
So the total amount of the drug immediately after the nth dose, in mg, is An = 40+ 40(0.10224) + 40(0.10224)^2 + ... + 40(0.10244)^(n-1)
An = 40[1 - (0.010224)^n]/(1 - 0.10224)
3 Write a broad expression for the quantity of the drug in the patient directly before taking the nth dose of the drug
Pn = An – 40
= 40(0.10224) + 40(0.10224)^2 + ... + 40(0.10244)^(n-1)
= 40(0.10224) [1 - (0.10224)^(n-1)]/(1 – 0.10224)
= 4.0895 [1 - (0.10224)^(n-1)]
4 What is the long-term minimum amount of drug in the patient?
= lim n-->infinity of Pn
= lim n-->infinity of 4.0895[1 - (0.10224)^(n-1)]
= 4.0895(1 - 0)
= 4.0895 mg.
It is a supernova that is thought to be a result of a explosion of a carbon-oxygen white dwarf in a binary system.
Answer:
An unknown number of identical light bulbs are connected to a 15 V battery in parallel. The current through the battery is 2 A. If the light bulbs are connected to the battery in series, the current through the battery is 5 mA. How many bulbs are there?
3 bulbs are there from the analogy given above
Explanation: