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: 66 degrees
Explanation:
Check out the attached image below. Figure 1 is the original image without any additions or alterations. Then in figure 2, I extend segment BC to form a line going infinitely in both directions. This line crosses segment DE at point F as shown in the second figure.
Note how angles ABC and DFC are alternate interior angles. Because AB is parallel to DE (given by the arrow markers) this means angle DFC is also 24 degrees
Focus on triangle DFC. This is a right triangle. The 90 degree angle is at C.
So we know that the acute angles x and 24 are complementary. They add to 90. Solve for x
x+24 = 90
x+24-24 = 90-24
x = 66
That is why angle CDE is 66 degrees
