Answer:
2,674.14 g
Step-by-step explanation:
Recall that the formula for radioactive decay is
N = N₀ e^(-λt)
where,
N is the amount left at time t
N₀ is the initial amount when t=0, (given as 42,784 g)
λ = coefficient of radioactive decay
= 0.693 ÷ Half Life
= 0.693 ÷ 18
= 0.0385
t = time elapsed (given as 72 years)
e = exponential constant ( approx 2.7183)
If we substitute these into our equation:
N = N₀ e^(-λt)
= (42,787) (2.7183)^[(-0.0385)(72)]
= (42,787) (2.7183)^(-2.7726)
= (42,787) (0.0625)
= 2,674.14 g
Answer:
Weight of the solution = 250 grams
Step-by-step explanation:
1) Consider the weight of solution as x grams.
32 % solution = 80 grams salt
32% of x = 80
(32/100)*x = 80
Solving for x:
x = (80*100) / 32
x = 250 grams
Answer: 21.9ft
Step-by-step explanation: please see attachment for explanation. Thanks.!
Answer:
D
Step-by-step explanation:
It turns out from similar triangles, that 7/BD = BD / 18. Use triangles ABD and BDC to show this relationship. Solving this equation will give you BD
BD^2 = 7*18
BD^2 = 126 Just leave it in this form. Do your rounding at the end.
Because triangle BDC is a right angle triangle, use the Pythagorean Theorem to solve for m
m^2 = BD^2 + 7^2
m^2 = 126 + 49
m^2 = 175 Take the square root of both sides.
sqrt(m^2) = sqrt(175)
m = 13.22
so the answer is D
