Answer: thank yuu
Step-by-step explanation:
Suppose after 2500 years an initial amount of 1000 grams of a radioactive substance has decayed to 75 grams. What is the half-life of the substance? The half-life is:_______.
(A) Less than 600 years
(B) Between 600 and 700 years
(C) Between 700 and 800 years
(D) Between 800 and 900 years
(E) More than 900 years
Answer:
The correct answer is:
Between 600 and 700 years (B)
Step-by-step explanation:
At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:
[tex]A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years[/tex]
First, let us calculate the decay constant (k)
[tex]75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036[/tex]
Next, let us calculate the half-life as follows:
[tex]\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years[/tex]
Therefore the half-life is between 600 and 700 years
Manuel can walk 5 miles In one hour. At this rate, how many miles can he walk in 8 minutes? Round to the nearest tenth
Answer:0.6666664
Step-by-step explanation:
You take 5 and divide by 60. Then multiply by 8.
2/3 of a mile.
If he can walk 5 MILES a hour, lets use 5/60.
Multiply 5/60 by 8 since each minute he travels 5/60 of a MILE.
You get 0.66(repeating) OR 2/3
Question Help When purchasing bulk orders of batteries, a toy manufacturer uses this acceptance sampling plan: Randomly select and test 36 batteries and determine whether each is within specifications. The entire shipment is accepted if at most 2 batteries do not meet specifications. A shipment contains 3000 batteries, and 3% of them do not meet specifications. What is the probability that this whole shipment will be accepted? Will almost all such shipments be accepted, or will many be rejected?
Answer:
The probability is [tex]P(X \le 2 ) = 0.9072[/tex]
The company will accept 90.72% of the shipment and will reject [tex](100 -90.72) = 9.2\%[/tex] of the shipment , so many of the shipment are rejected
Step-by-step explanation:
From the question we are told that
The sample size is n = 36
The proportion that did not meet the requirement is [tex]p = 0.03[/tex]
Generally the probability that the whole shipment is accepted is equivalent to the probability that there is at most 2 batteries that do not meet the requirement , this is mathematically represented as
[tex]P(X \le 2 ) = [ P(X = 0 ) + P(X = 1 ) + P(X = 0)][/tex]
=> [tex]P(X \le 2 ) = [ [^{n}C_0 * (p)^{0} *(1-p)^{n-0} ] + [^{n}C_1 * (p)^{1} *(1-p)^{n-1} ] + [^{n}C_2 * (p)^{2} *(1-p)^{n-2} ]][/tex]
Here C stands for Combination (so we will be making the combination function in our calculators )
So
=> [tex]P(X \le 2 ) = [ [^{36}C_0 * (0.03)^{0} *(1-0.03)^{36-0} ] + [^{36}C_1 * (0.03)^{1} *(1-0.03)^{36-1} ] + [^{36}C_2 * (0.03)^{2} *(1-0.03)^{36-2} ]][/tex]
=> [tex]P(X \le 2 ) = [ [1 * 1 * 0.3340 ] + [36* 0.03 *0.3444 ] + [630 * 0.0009 *(0.355 ]][/tex]
=>[tex]P(X \le 2 ) = 0.9072[/tex]
The company will accept 90.72% of the shipment and will reject [tex](100 -90.72) = 9.2\%[/tex] of the shipment , so many of the shipment are rejected
I don't believe I was shown how to complete this
Caleb and Emily are standing 100 yards from each other. Caleb looks up at a 45° angle to see a hot air balloon. Emily looks up at a 60° angle to see the same hot air balloon. Approximately how far is the hot air balloon off the ground?
a) 44.3 yd.
b) 63.4 yd.
c) 73.2 yd.
d) 89.7 yd.
Answer:
B. 63.4 yards.
Step-by-step explanation:
I'm a little confused.
(2y+14.6+3.8)-(34.8m+15.6+2y)
Answer:
5.6
Step-by-step explanation:
You most likely will end up putting it in slope form y=mx+b
(2y+14.6+3.8)-(34.8m+15.6+2y) collect like terms
(2y+18.4)-(34.8m + 15.6 + 2y) = 2.8 + 34.8m
2y-2y= 0
18.4 - 15.6= 2.8
34.8m -0 = 34.8m
2.8 + 34.8m ( I think we should further simplify)
so minus 2.8 on both sides
34.8m = -2.8(divide by 34.8 on both sides)
m = -7/87
Plug in
(2y+14.6+3.8)-(34.8(-7/87)+15.6+2y) collect like terms
(2y+18.4)-(-2.8 + 15.6 + 2y) collect like terms
(18.4)-(12.8)= 5.6
2y-2y = 0
34.8(-7/87)= -2.8
18.4 - 12.8 = 5.6
At a school, there are 120 athletes. The ratio of boy athletes to giri athletes is 3:5. How many of the athletes are girls?
А
75
B
45
с
24
D 5
Answer:
a
Step-by-step explanation:
because there are over half girls and half of 120 is 60 and 75 is over half
The zeroes of the function are:
A) -2 and 0
B) 0 and 4
C) -2, 0, and 4
Hannah wants to buy a $460 camera. She can save $35 each week from her paycheck. However, before Hannah can buy the camera, she must give her brother $65 that she owes him. For how many weeks will Hannah need to save before she can pay back her and buy the camera?
Answer:
460+65=525/35=15 15 weeks
Help with this one please
Answer:
(3x - 14) (2x - 7)
I hope this helps!
What is the answer for number 12
What kind of lines are shown?
Answer:
vertical and horizontal
Solve: x^2=10
A) x= +5
B) x= +100
C) x= +3.5
D) x= 10 squared
Answer:
D) x=√10
Step-by-step explanation:
√(10)=3.16(approximately )
The temperature at 6 a.m. was −12°F. At 11 a.m. the temperature was 0°F. Which of the following shows the temperature change from 6 a.m. to 11 am?
Answer:
+12 degrees
Step-by-step explanation:
You never showed a picture, but im pretty sure this is correct
I hope this helped, please mark Brainliest, thank you!
28 points. I need help ASAP please
Answer:
1) Thousands
2) 5
3) ten million
4) 3,000,000
Step-by-step explanation:
Answer:
1. hundred thousands
2. 5
3. ten millions
4. 3,000,000
Step-by-step explanation:
PLEASE HELP
For spirit week at a local high school, students were encouraged to wear their school colors of green and white. 1,200 students wore their school colors while 300 students did not wear green and white. What percent of the school population did NOT wear their school colors?
Here are the answer choices
A.
15%
B.
20%
C.
25%
D.
33%
Answer:
C. 25% The correct answer is C. 300 divided by 1200 equals 25%.
Step-by-step explanation:
Answer:
B.) 20%
Step-by-step explanation:
First, add 1,200 and 300. That gives you 1,500. You want to find how much percent of 1,500 equals 300, and that is 20%.
The set A = {1, 3, 5}. What is a larger set this might be a subset of?
Answer:
Step-by-step explanation:
A larger set that a particular set can be a subset of is a Universal set. A universal set is parent where all other sets are derived from.
For example, given a universal set U = {1,2,3,4,5}, a set A = {1, 3, 5} is said to be a subset of the set U because the elements of set B are contained in the Universal set U.
Also, sets like {1, 4,5} and {3,4,5} can also be regarded as the subset of U since all the elements of the sets can be found in the Universal set U. Hence the correct name of the set is a UNIVERSAL SET
So, the number of maximum subsets we can create from the given set is 8.
Subsets:The subsets of any set consists of all possible sets including its elements and the null set. Let us understand with the help of an example.
Example: Find all the subsets of set A = {1,2,3,4}
Solution: Given, A = {1,2,3,4}
Subsets =
The subsets of any set consisting of all possible sets including its elements and the null set. Let us understand with the help of an example.
Example: Find all the subsets of set A = {1,2,3,4}
{}
{1}, {2}, {3}, {4},
{1,2}, {1,3}, {1,4}, {2,3},{2,4}, {3,4},
{1,2,3}, {2,3,4}, {1,3,4}, {1,2,4}
{1,2,3,4}
So, the formula is [tex]2^n[/tex].
The given set is,
[tex]A = \{1, 3, 5\}[/tex]
Here the number of an element is 3.
So, the maximum number of subsets we can create is,
[tex]2^n=2^3=8[/tex]
Learn more about the topic Subsets:
https://brainly.com/question/17514113
Can you please simplify c5 x c
Answer:
5c^2
Step-by-step explanation:
i think c is a variable so,
5xcxc = 5c^2
15 tens 7 ones what is the answer?
Answer:
157
Step-by-step explanation:
Answer: 15 tens and 7 ones in standard form would be 157. If you have 15 tens this means that you are adding 10, 15 times or multiplying 10 by 15, which gives you 150.
Step-by-step explanation: Hopefully this helped!
7 days left until launch of products with $668 left in budget. Need to spend $85 on last day. How many dollars do we spend on remaining days?
Answer:
In total, you have $668.00.
To reserve enough for the last day, you need to subtract the last day's budget:
This means that, for the remaining 6 days in the week, you have $583.00.
Assuming an equal amount is being spent each day, you can calculate the daily budget by dividing the remaining total by the number of days left.
To avoid going over budget, you can spend $97.16 per day for the other six days.
Hope this helps!
Step-by-step explanation:
To visit the top of the Empire State building , a ticket in 1999 cost four dollars , in 2019 the same ticket cost $32 ,what was the percentage change in the cost of the ticket ?
Answer:
700%
Step-by-step explanation:
The formula to find the percentage is found below =
[tex]\frac{changeinvalue}{absolutevalueoftheoriginalvalue} * 100[/tex]
So to find the change in value, we must subtract 32 from 4, which gets us -28.
We know the og value already, 4 dollars.
So do the division
[tex]\frac{-28}{4} =-7[/tex]
Now the multiplcation,
-7 * 100
-700
700%
I want to decorate my room with leaves and turkeys for Thanksgiving. The number of leaves is twenty more than twice the number of turkeys. The number of leaves is ten less than 4 times the number of turkeys. How many of each type of decoration should I use?
Answer:
50 leaves, 15 turkeys
Step-by-step explanation:
set up an equation
l = leaves
t = turkeys
l = 2t+20
l = 4t-10
2t+20=4t-10
30=2t
15=t (so that means that there would be 15 turkey decorations, but we're not done yet)
substitute (either equation):
l = 2(15)+20
l = 30+20
l = 50 (so this means there would be 50 leaves)
hope this helps!
A journalist interviews 123 people after they leave a restaurant and asks them how confident they are that the food is safe.
Answer:
what do I need to do to answer
Step-by-step explanation:
Paul and Seth know that one point on the line
Answer:
what
Step-by-step explanation:
Julie earned $130 one week and $125.50 the next week. After depositing these amounts in her account, she had a total of $335.
How much was already in her account before she deposited the $130 and $125.50?
Answer:
she had more than me
Step-by-step explanation:
Answer: $79.50
Step-by-step explanation:
Add together $130 and $125.50 to find out how much she deposited.
$130+125.50=$255.50
Now subtract the amount that was deposited from the total amount in her account.
$335−$255.50=$79.50
Will give brainliest if correct what is the discriminant of the quadratic equation: (multiple choice)
What is the opposite of the opposite of -1.4?
Answer:
-1.4
Step-by-step explanation:
opposite of -1.4 = 1.4
opposite of the opposite of -1.4 = the opposite of 1.4 = -1.4
Gwendolyn was physically present in the United States for 96 days in 2019, 198 days in 2018, and 66 days in 2017. Under the substantial presence test formula, how many days is Gwendolyn deemed physically present in the United States in 2019 g
Answer:
173 days
Step-by-step explanation:
The formula for substantial presence test is;
SBT = (Total of number of days present in the current tax year) + (1/3)(number of days in the year that was before the tax year) + (1/6)(number of days in the year that was two years before the tax year)
From the question, present tax year is 2019 and number of days is 96 days.
Year before tax year is 2018 and number of days is 198 days
2 years before tax year is 2017 and number of days is 66 days.
Thus;
SBT = 96 + ((1/3)198) + ((1/6)66)
SBT = 173 days
Th e expert trail is 750 meters longer than the beginner trail. How long is each trail?
do they give the whole amount of both trails together? then someone would be able to answer this so pls add that
I need help with a math problem comment if u want i really need help with this