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3 years ago

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Sean is conducting an experiment with an isotope of a particular element that has a half life of 4 hours. He begins with a sampl

e of the isotope with a mass of 92 grams. He then measures the mass of the object every hour. What is the approximate mass of the sample after 20 hours. Choices are: A: 2.875 B:2,944 C:1.4375 D:0.0313

1 answer:

Alex Ar [27]3 years ago

5 0

Answer:

/??

Step-by-step explanation:

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Russell runs 9/10 mile in 5 minutes. At this rate, how many miles can he run in one minute?

miss Akunina [59]

9/50 is the answer I think!

I converted 9/10 to decimal to make it easier for me to solve and got 0.9

I divided 0.9 by 5 and got 0.18

I converted 0.18 to fraction and got 9/50

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3 years ago

(gof)(x) = x2 + x + 1

Sever21 [200]

Answer:

$the \: answer \: is \: b$

Step-by-step explanation:

$(gof)x = {(x + 1)}^{2 } = {x}^{2} + 2x + 1$

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2 years ago

My sister can walk from school to home in 35 minutes. I can walk from school to home in 20 minutes. But today I stayed for some

Verizon [17]

Answer:

you both will reach the home at the same time.

I) You can catch your sister.

ii) Reason: you both will reach home at the same time.

Step-by-step explanation:

Let "d" be distance from school to home.

Let's find the speed of you and your sister.

Speed = $\frac{Distance}{Time}$

Your speed = $\frac{d}{20}$

Your sister's speed = $\frac{d}{35}$

Today, You stayed for some extra help by the time your sister covered $\frac{3}{7}$ of the way home.

Remaining distance to reach the home = $1 - \frac{3}{7}d = \frac{7-3}{7}d = \frac{4}{7}d$

=

Now let's find the time to be taken your sister to reach the home.

Time = $\frac{distance}{speed}$

= $\frac{\frac{4}{7}d }{\frac{1}{35} d} = \frac{4}{7} *\frac{35}{1} = 20$

So, your sister will take 20 minutes to get home by the time your start.

We know that it takes you 20 minutes to reach your home.

Therefore, you both will reach the home at the same time.

I) You can catch your sister.

ii) Reason: you both will reach home at the same time.

7 0

2 years ago

Carol bought 12 pounds of bananas for $13.50 and then the next week she bought 20 pounds for $22. Which bunch of bananas was the

DENIUS [597]

The answer is B) 20 lbs for $22 because carol is getting 8 pounds more for only $9+

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2 years ago

The antibiotic clarithromycin is eliminated from the body according to the formula A(t) = 500e−0.1386t, where A is the amount re

PolarNik [594]

Answer:

Time(t) = 11.61 hours (Rounded to two decimal place)

Step-by-step explanation:

Given: The antibiotic clarithromycin is eliminated from the body according to the formula:

$A(t) = 500e^{-0.1386t}$ ......[1]

where;

A - Amount remaining in the body(in milligram)

t - time in hours after the drug reaches peak concentration.

Given: Amount of drug in the body is reduced to 100 milligrams.

then,

Substitute the value of A = 100 milligrams in [1] we get;

$100= 500e^{-0.1386t}$

Divide both sides by 500 we get;

$\frac{100}{500}=\frac{ 500e^{-0.1386t}}{500}$

Simplify:

$\frac{1}{5} = e^{-0.1386t}$

Taking logarithm both sides with base e, then we have;

$\log_e (\frac{1}{5})= \log_e (e^{-0.1386t})$

$\log_e (\frac{1}{5})=-0.1386t$ [ Using $\log_e e^a =a$ ]

or

$\log_e (0.2)=-0.1386t$

$-1.6094379124341 = -0.1386t$

[using value of $\log_e (0.2) = -1.6094379124341$ ]

then;

$t = \frac{-1.6094379124341}{-0.1386}$

Simplify:

t ≈11.61 hours.

Therefore, the time 11.61 hours(Rounded two decimal place) will pass before the amount of drug in the body is reduced to 100 milligrams

6 0

2 years ago