Answer:
14.99 hours
Step-by-step explanation:
The formula for half-life is given as,
R/R' = 2ᵃ/ᵇ...................... Equation 1
Where R= Original mass of sodium-24, R' = mass of Sodium-24 after disintegration, a = Total time taken for sodium-24 to disintegrate, b = half-life of sodiun-24.
Given: R = 1 kg, R' = 0.0156 kg, a = 90 hours
Substitute into equation 1 and solve for b
1/(0.0156) = 2⁹⁰/ᵇ
Taking the log of both side
log[1/(0.0156)] = log(2⁹⁰/ᵇ)
log[1/(0.0156)] = 90/b(log2)
90/b = log[1/(0.0156)]/log2
90/b = 6.0023
b = 90/6.0023
b = 14.99 hours
b = 14.99 hours.
Hence the half-life of Sodium-24 is 14.99 hours
Answer:
number of dimes 11 to 14
Step-by-step explanation:
given data
coin = 19
worth no less = $1.30
Nolan nickles = 5
solution
we convert 5 cent to dollars, it will be
5÷100 = $0.05
and
dime is worth 10 cents
so it will be 10 ÷ 100 = $0.1
so we consider here x as the number when nickels.
and we consider y as the number of dimes.
so here we can say
x + y ≤ 19 ..........................1
as here no less than $1.30 combined.
so
0.05 x + 0.1 y ≥ 1.3 ......................2
and
when Nolan has 5 nickels
put x = 5 in eq 1
5 + y ≤ 19
y ≤ 19 - 5
y ≤ 14
and
now we put x = 5 in eq 2
0.05 × 5 + 0.1y ≥ 1.3
0.25 + 0.1y ≥ 1.3
0.1y ≥ 1.3 - 0.25
0.1y ≥ 1.05
y ≥ 10.5
so all possible values for the number of dimes 11 to 14
<span>We know that
there is no universal acceptance meaning of a percentile. When someone told you
that you are in the 80th percentile, the meaning of that is you
have achieved the lowest score that is greater than 80 percent of the score. It is calculated by using the formula <span>R = P/100 x (N + 1)</span></span>
Answer:33.3
Step-by-step explanation: a mile is 1000×3 so it's 3000/90
Answer:
Width = 12 in
Length = 16 in
Step-by-step explanation:
Let, the Width of the rectangle = w in
Now, the length of the rectangle = (w + 4) in
Now, Perimeter = 56 in
Also, we know that
Perimeter of the Rectangle = 2 (Length +Width)
or, 2 (Length +Width) = 56
⇒ 2(w + 4 +w) = 56
or, 4w =56 -8
width = 12 in
So, Length = w + 4 = 12 + 4 = 16 in
