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:
The perimeter is 92 ft
Step-by-step explanation:
Add all of the sides up
Answer:
19.1 miles
Step-by-step explanation:
The situation given represents a right triangle.
Thus, we would use trigonometric function to find how far north the boat travelled.
Let's represent how far the boat travelled north with "x".
Thus:
Reference angle = 23°
Opposite = x
Adjacent = 45 miles
Apply TOA:
Tan 23° = Opp/Adj
Tan 23° = x/45
Multiply both sides by 45
45 × Tan 23° = x
x = 45 × Tan 23°
x = 19.1013667
x = 19.1 miles (nearest tenth of a mile)
In a sequence of events, the
total possible number of ways all events can performed is the product of the
possible number of ways each individual event can be performed. Since there
are 10 openings
<span>P = 40 x 39 x 38 x 37 x 36 x 35
x 34 x 33 x 32 x 31 = 3.07599 x 10^15 different combinations</span>
Answer:
8 1/2 hrs/wk
Step-by-step explanation:
3(1 1/2 hrs) plus
2(1 1/4 hrs) plus
2(3/4 hr)
The LCD here is 4. Convert 3(1 1/2 hrs) to 3(1 2/4 hrs), so that we now have:
3(1 2/4 hrs) = 3 6/4 hrs
+2(1 1/4 hrs) = 2 2/4 hrs
+2(3/4 hrs) = 6/4 hrs
-------------------------------------
5 14/4 hrs, or
5 + 3 2/4 hrs, or
8 1/2 hours/week
