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
7y+5-8y+6
Group like terms
7y-8y+5+6
-y+11
or 11-y
Answer:
Option 4. 256 - 64π is the correct option.
Step-by-step explanation:
In the given picture a square is circumscribed about a circle with a side = 2r
where r is the radius of the circle.
Therefore area of the square = (2r)² = 4r² = 4 × 8² = 4 × 64 = 256 in²
Now area of the circle = πr² = π × 8² = 64π in²
Now area of region that is inside the square and outside the circle =
Area of square - area of circle = (256 - 64π) in².
Therefore the answer is (256 - 64π).
Answer:
what is the rest of the question?
Step-by-step explanation:
The answer should be 3 hours and 45 minutes if i did the math in my head correctly
