2022-05-09
An unknown radioactive element decays into non-radioactive substances. In 780 days, the radioactivity of a sample decreases by 59 percent.
(a) What is the half-life of the element?
half-life: (days)
Round to two decimal places.
(b) How long will it take for a sample of 100 mg to decay to 47 mg?
time needed: (days)
Round to two decimal places.
star233
Skilled2022-05-13Added 403 answers
Govering equation: (1)
where is the amount of the element at
Now, when ,
So,
So, (1) becomes
a) Let when
Then
So, the half-life of the element is days
b) Let be the time taken by a sample of to decay to
Then
Hence, the time required to decay to is
Find the volume V of the described solid S
A cap of a sphere with radius r and height h.
V=??
Whether each of these functions is a bijection from R to R.
a)
b)
c)
In how many different orders can five runners finish a race if no ties are allowed???
State which of the following are linear functions?
a.
b.
c.
d.
Three ounces of cinnamon costs $2.40. If there are 16 ounces in 1 pound, how much does cinnamon cost per pound?
A square is also a
A)Rhombus;
B)Parallelogram;
C)Kite;
D)none of these
What is the order of the numbers from least to greatest.
,
,
,
Write the numerical value of
Solve for y. 2y - 3 = 9
A)5;
B)4;
C)6;
D)3
How to graph ?
How to graph using a table?
simplify
How to find the vertex of the parabola by completing the square ?
There are 60 minutes in an hour. How many minutes are there in a day (24 hours)?
Write 18 thousand in scientific notation.