Answer:
464 grams.
Step-by-step explanation:
Amount of substance:
The amount of substance after t years is given by an equation in the following format:
In which A(0) is the initial amount and r is the decay rate, as a decimal.
Co-60 has a half life of 5.3 years.
This means that:
We use this to find r. So
![\sqrt[5.3]{(1-r)^{5.3}} = \sqrt[5.3]{0.5}](https://tex.z-dn.net/?f=%5Csqrt%5B5.3%5D%7B%281-r%29%5E%7B5.3%7D%7D%20%3D%20%5Csqrt%5B5.3%5D%7B0.5%7D)
So
If a pellet that has been in storage for 26.5 years contains 14.5g of Co-60, how much of this radioisotope was present when the pellet was put in storage?
We have that 
, and use this to find A(0). So
[tex]A(0) = 464[tex]
464 grams.
Answer:
a=3
Step-by-step explanation:
This should be very simple, just substitute xy and y for 5 and 7 respectively, so 5a-2*7=1, or 5a-14=1, or 5a=15, if we divide both sides by 5, we get a=3
Answer:
⅓ m/s
Step-by-step explanation:
Area of a square is:
A = s²
Take derivative of both sides with respect to time:
dA/dt = 2s ds/dt
Given that dA/dt = 6 m²/s and s = 9 m:
6 m²/s = 2 (9 m) ds/dt
ds/dt = ⅓ m/s
Answer:
x=6
Step-by-step explanation:
5x+2=32
Step 1: Subtract 2 from both sides.
5x+2−2=32−2
5x=30
Step 2: Divide both sides by 5.
5x
5
=
30
5
x=6
Answer:
2.12%
Step-by-step explanation: So in a 52 card deck, there are 13 hearts, so our probability of drawing a heart on the first try is 13/52, but this 3 decks, so you pretty much just add
