Answer:
It is the 3rd one 9/5y+9.
Answer:
29.25
Step-by-step explanation:
(8 x 2.25) + (9 x 1.25)
18 + 11.25
29.25
i hope this helps
The correct answer is 0.99kg/L
Explanation:
To find the density, the first step is to convert the weight (mass) and the volume into the appropriate units.
The volume is 8.5 gallons and this needs to be converted to litters. In this case, multiply the volume in gallons by 3.785 because each gallon contains 3.785 liters.
8.5 x 3.785 = 32.1725 liters
The mass is 70 pounds and this needs to be converted to kilos. In this case, divide the pounds by 2.204 considering each kilo contains 2.204 pounds.
70 ÷ 2.2046 = 31.751 kilos
Now, find the density by dividing the mass into the volume.
Density= 31.751 kg ÷ 32.1725 L
Density = 0.98 kg/L
This means the density is 0.9.868 kg/L and this can be rounded as 0.99 kg/L
Is that the whole problem?
<u>Finding the Decay constant(λ):</u>
λ = 0.693 / (half-life)
we are given that the half-life is 36 hours
λ = 0.693 / (36)
λ = 0.01925 /hour
<u>Time taken for 87% decay:</u>
Since decay is first-order, we will use the formula:
Where A₀ is the initial amount and A is the final amount
Let the initial amount be 100 mg,
the final amount will be 87% of 100
Final amount = 100*87/100 = 87 mg
<em>Replacing the values in the equation: </em>
<em />
<em />
<em />
<em />
t = 7.18 hours
<em>We used 'hours' as the unit because the unit of the decay constant is '/hour'</em>
Therefore, the drug will decay to 87% of initial dosage after 7.18 hours
