The answer to this problem is 8 I believe. I hope you do good
Answer:
The amount of Polonium-210 left in his body after 72 days is 6.937 μg.
Step-by-step explanation:
The decay rate of Polonium-210 is the following:
(1)
Where:
N(t) is the quantity of Po-210 at time t =?
N₀ is the initial quantity of Po-210 = 10 μg
λ is the decay constant
t is the time = 72 d
The decay rate is 0.502%, hence the quantity that still remains in Alexander is 99.498%.
First, we need to find the decay constant:
(2)
Where t(1/2) is the half-life of Po-210 = 138.376 days
By entering equation (2) into (1) we have:
Therefore, the amount of Polonium-210 left in his body after 72 days is 6.937 μg.
I hope it helps you!
Answer:
8 and 9
Step-by-step explanation:
8² = 64, and 9² = 81. Equivalently, √64 = 8 and √81 = 9. Since 67 is between 64 and 81, √67 must be between 8 and 9.
Answer:
$1000 + $25m and $1300 - 25m ;
1100 + 2.75m
2010 (4th month)
2011 ( 7th month)
Step-by-step explanation:
Joline's account :
Initial deposit = $1000
Monthly deposit = $25
Monthly withdrawal = $25
Number of months = 12
Let m = number of month at any point in time
Initial deposit + total deposit
Amount in Joline's account ; first 12 months
$1000 + $25m - - - (1)
Next 12 months :
$1000 + $25 *12 - 25m
1300 - 25m
Sofia's account :
Deposit amount = $1100
Interest per month = 0.25% = 0.0025
1100 + (1100 * 0.0025 * m)
1100 + 2.75m - - (2)
To find the month:
Equate equation 1 and 2, then find m
$1000 + $25m = 1100 + (1100*0.0025*m)
1000 + 25m = 1100 + 2.75m
25m - 2.75m = 1100 - 1000
22.25m = 100
m = 100 / 22.25
m = 4.494
In year 2010, they have approximately the same amount in the fourth month
1300 - 25m = 1100 + 2.75m
1300 - 1100 = 2.75m + 25m
200 = 27.75m
m = 200 / 27.75
m = 7.207
In 2011 ; they have approximately the se amount in the 7th month
Since it could drive 49 miles on 1 gallon, and this is also it's gas mileage, (because 490/10=49) it could drive 45 times more on 45 gallons than on one. So, we multiply 45 by 49 to get 2209 gallons on 45 gallons of gas.
