I need to figure out the volume and do all the work can u help me

Krypton-91 is a radioactive substance that decays very quickly. The function Q(t)=Qoe^-kt models radioactive decay of krypton-91

Masteriza [31]

The "k" value should have units and should be negative.
k = -.07 / seconds
Half-Life = ln (.5) / k
Half-Life = ln (.5) / -.07
Half-Life = -.693147 / -.07
Half-Life = 9.9 seconds
(actually, wkpedia says half-life of Krypton 91 is 8.57 seconds)

elapsed time = half-life * log (bgng amt / end amt) / log (2)
elapsed time = 9.9 * log (100 / 10) / 0.30102999566
elapsed time = 9.9 * 1 / 0.30102999566
elapsed time = 9.9 * 3.3219280949 
elapsed time = 32.8870881395 
elapsed time = 32.89 seconds (rounded)

Source:
http://www.1728.org/halflife.htm

6 0

3 years ago

Read 2 more answers

Please Answer Quick 65 Points ! !

NeTakaya

The correct answers are:

The ordered pair (7, 19) is a solution to the first equation because it makes the first equation true.

The ordered pair (7, 19) is not a solution to the system because it makes at least one of the equations false.

Further explanation:

Given equations are:

2x-y = -5

x+3y = 22

We have to check whether the given statements are true or not. In order to find that we have to put the points in the equations

Putting the point in 2x-y = -5

$2x - y = -5\\2(7) -19 = -5\\14-19 = -5\\-5 = -5$

Putting the point in x+3y=22

$7 + 3 (19) = 22\\7 + 57 = 22\\64 \neq 22$

The point satisfies the first equation but doesn't satisfy the second. So,

1. The ordered pair (7, 19) is a solution to the first equation because it makes the first equation true.

This statement is true as the point satisfies the first equation

2. The ordered pair (7, 19) is a solution to the second equation because it makes the second equation true.

This Statement is false.

3. The ordered pair (7, 19) is not a solution to the system because it makes at least one of the equations false.

This statement is true.

4. The ordered pair (7, 19) is a solution to the system because it makes both equations true.

This statement is false as the ordered pair doesn't satisfy both equations.

Keywords: Solution of system of equations, linear equations

Learn more about solution of linear equations at:

#LearnwithBrainly

5 0

3 years ago

29 less than -10 times a number is equal to -18 times a number +91

sergejj [24]

Answer:

10

Step-by-step explanation:

5 0

3 years ago

A college student is interested in testing whether business majors or liberal arts majors are better at trivia. The student give

attashe74 [19]

Answer:

There is no significant difference between the two averages at 5% level

Step-by-step explanation:

Given that a a college student is interested in testing whether business majors or liberal arts majors are better at trivia.

The student gives a trivia quiz to a random sample of 30 business school majors and finds the sample’s average test score is 86. He gives the same quiz to 30 randomly selected liberal arts majors and finds the sample’s average quiz score is 89

Thus he has done a hypothesis testing for comparison of two means of different subjects. n =30

$H_0: Mean of business majors = Mean of liberal arts majos\\H_a:Mean of business majors \neq Mean of liberal arts majos$

Since which is better is not claimed we use two tailed test here

We find that p value $= 0.0524 >5%$ our alpha

Since p >alpha, we find that there is no significant difference between the averages of these two groups and null hypothesis is accepted

4 0

3 years ago

A minor league baseball team plays 72 games in a season. If the team won 15 more than twice as many games as they lost, how many

Alina [70]

X = games won
y = games lost

x + y = 72
x = 2y + 15

2y + 15 + y = 72
3y + 15 = 72
3y = 72 - 15
3y = 57
y = 57/3
y = 19 <=== lost games

x = 2y + 15
x = 2(19) + 15
x = 53 <=== won games

3 0

2 years ago