Answer:
The mass of the radioactive sample after 40 minutes is 12.8 g.
Step-by-step explanation:
The mass of the sample can be found by using the exponential decay equation:

Where:
N(t): is the amount of the sample at time t =?
N₀: is the initial quantity of the sample = 120 g
t = 40 min
λ: is the decay constant = 0.056 min⁻¹
Hence, the mass of the sample after 40 min is:

Therefore, the mass of the radioactive sample after 40 minutes is 12.8 g.
I hope it helps you!
Answer:
Imagine an easier version of this problem: You have a board 5 feet long that you must cut (divide, right?) into two equal parts. It is probably clear to you that you simply divide the length (5) by the number of parts you're dividing it into (2) to obtain the length of each piece (2.5 feet).
Use the same method for your problem 5 feet divided by 6 is 0.83 feet per piece.
We do not ordinarily divide feet into decimal portions, but instead into inches. Since an inch is 1/12 of a foot, you could simply say 5/6 = how many twelfths? or 5/6 = n/12 Solve this by inspection or by cross multiplying 5 times 12 equals n times 6. So n must equal 10, and your pieces of board are each 10 inches long.
Answer:
126 square inches
Step-by-step explanation:
The area of the figure = area of the parallelogram + area of the square + area of the rectangle
✔️Area of the parallelogram = b*h
b = 10 in.
h = 3.5 in.
Area = 10*3.5
Area = 35 in.²
✔️Area of the square = s²
s = 4 in.
Area = 4²
Area = 16 in.²
✔️Area of the rectangle = L*W
L = 12.5 in.
W = 6 in.
Area = 12.5*6
Area = 75 in.²
✅Area of the figure = 35 + 16 + 75
= 126 in.²
Answer:
It's 8 the answer is 8
Step-by-step explanation:
10, 20w, 2w, and we are factors of 20w and 40wz