Answer:
10.5
Step-by-step explanation:
Answer:
Jelly beans: $6 for 1 kg
Gummy worms: $7 for 1 kg
Step-by-step explanation:
In this question, we need to find the cost of 1kg of jelly beans and gummy worms.
To do this, make equations for both scenarios and solve:
2j + 2g = 26
2j + 3g = 33
Turn the bottom equation negative, as we will first solve for gummy worms (g).
2j + 2g = 26
-2j - 3g = -33
Solve:
-g = -7
Divide both sides by -1.
g = 7
We now know that gummy worms cost $7 for 1 kg
To solve for jellybeans (j), plug in 7 to g in one of the equations and solve:
2j + 2(7) = 26
2j + 14 = 26
Subtract 14 from both sides.
2j = 12
Divide both sides by 2.
j = 6
Jellybeans cost $6 for 1 kg.
Check answer by plugging in values to one of the equations:
2(6) + 2(7) = 26
12 + 14 = 26
26 = 26
Answer:
the time taken for the radioactive element to decay to 1 g is 304.8 s.
Step-by-step explanation:
Given;
half-life of the given Dubnium = 34 s
initial mass of the given Dubnium, m₀ = 500 grams
final mass of the element, mf = 1 g
The time taken for the radioactive element to decay to its final mass is calculated as follows;
![1 = 500 (0.5)^{\frac{t}{34}} \\\\\frac{1}{500} = (0.5)^{\frac{t}{34}}\\\\log(\frac{1}{500}) = log [(0.5)^{\frac{t}{34}}]\\\\log(\frac{1}{500}) = \frac{t}{34} log(0.5)\\\\-2.699 = \frac{t}{34} (-0.301)\\\\t = \frac{2.699 \times 34}{0.301} \\\\t = 304.8 \ s](https://tex.z-dn.net/?f=1%20%3D%20500%20%280.5%29%5E%7B%5Cfrac%7Bt%7D%7B34%7D%7D%20%5C%5C%5C%5C%5Cfrac%7B1%7D%7B500%7D%20%3D%20%20%280.5%29%5E%7B%5Cfrac%7Bt%7D%7B34%7D%7D%5C%5C%5C%5Clog%28%5Cfrac%7B1%7D%7B500%7D%29%20%3D%20log%20%5B%280.5%29%5E%7B%5Cfrac%7Bt%7D%7B34%7D%7D%5D%5C%5C%5C%5Clog%28%5Cfrac%7B1%7D%7B500%7D%29%20%20%3D%20%5Cfrac%7Bt%7D%7B34%7D%20log%280.5%29%5C%5C%5C%5C-2.699%20%3D%20%5Cfrac%7Bt%7D%7B34%7D%20%28-0.301%29%5C%5C%5C%5Ct%20%3D%20%5Cfrac%7B2.699%20%5Ctimes%2034%7D%7B0.301%7D%20%5C%5C%5C%5Ct%20%3D%20304.8%20%5C%20s)
Therefore, the time taken for the radioactive element to decay to 1 g is 304.8 s.
Answer:
d - 7
Step-by-step explanation:
The word "difference" tells us that we will be using subtraction. Also, subtraction is not the same if you reverse the terms like, x - 2 and 2 - x are not the same. In your question it say "d and 7" so that's the order we use in the algebraic expression.
Since it starts at 50 and goes to 35....it is a decrease since the amount is going down, or getting smaller. To find the percent, first find the difference 50-35 = 15; then divide by the initial amount of 50. So, 15/50 = 0.3, and then convert that to a percent by multiplying by 100. Therefore the percent decrease is 30%
