Answer:
A) 277 million years
Step-by-step explanation:
Here, decay of U-238 is first order reaction. (since most of the nuclear decays are first order).
so, the equation t = 
× ln(
)
where, t = time from start of reaction
k = reaction constant
A(0) = initial concentration; A = present concentration.
⇒ 4.5 billion = 4500 million years = × ln2.
Now, given 95.82% of parent U-238 isotope is left.
⇒ t = × ln()
t = 
× ln(
)
⇒ t ≅ 277 million years.
If sandy has 8 and alex has 6 fewer than alex has 2. Since Jill has 2 then you add 8 plus 2 plus 2 which equals 12. So there is 12 all together
t = 5.3 years
(about 5 years 4 months)
Equation:
t = (1/r)(A/P - 1)
Calculation:
First, converting R percent to r a decimal
r = R/100 = 7.2%/100 = 0.072 per year,
then, solving our equation
t = (1/0.072)((4835.6/3500) - 1) = 5.3
t = 5.3 years
Answer:
if am right it's 90
Step-by-step explanation:
Answer:
4 1/10 kg
Step-by-step explanation:
To find the total mass, we add the mass of the three baskets
1 1/10 + 1 3/10 + 1 7/10
Since they have the same denominator
1 1/10
1 3/10
1 7/10
-------------
3 11/10
Change the improper fraction to a mixed number
11/10 = 1 1/10
3 + 1 1/10
4 1/10
