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:
x = -6 x= -3
Step-by-step explanation:
f(x) = x^2+9x+18
Set equal to 0 to find the zeros
0 = x^2+9x+18
Factor, what numbers multiply to 18 and add to 9
6*3 =18
6+3=9
0= (x+6) (x+3)
Using the zero product property
x+6 =0 x+3 =0
x = -6 x= -3
Answer:
$192.4
Step-by-step explanation:
First, we'll work out what the customer had to pay before tax.
That's
(USD)
4% of 185 is 7.4,
So the customer paid
(USD)
Answer:
x = 11/2
Step-by-step explanation:
just go by each step
Answer:
Step-by-step explanation:
