Answer:
radioactive dating of rocks
In terms of x, what are the dimensions of a rectangle whose area is represented by the
expression 49x2 - 16?
Please help
A rock is thrown upward from the top of a high cliff overlooking the ocean at a speed of 96 feet per second . The rock's height above ocean can be modeled by the equation H(t) = - 16t ^ 2 + 96t + 112 . How long will it take seconds for the rock to hit the ocean? Do not include units in your answer.
Answer:
7
Step-by-step explanation:
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]
[tex]\Delta = b^{2} - 4ac[/tex]
In this question:
The height of the rock after t seconds is given by the following equation:
[tex]H(t) = -16t^2 + 96t + 112[/tex]
How long will it take in seconds for the rock to hit the ocean?
This is t for which:
[tex]H(t) = 0[/tex]
So
[tex]-16t^2 + 96t + 112 = 0[/tex]
Simplifying by -16
[tex]t^2 - 6t - 7 = 0[/tex]
So a quadratic equation with [tex]a = 1, b = -6, c = -7[/tex]
[tex]\Delta = b^{2} - 4ac = (-6)^2 - 4*1*(-7) = 36 + 28 = 64[/tex]
[tex]t_{1} = \frac{-(-6) + \sqrt{64}}{2*1} = 7[/tex]
[tex]t_{2} = \frac{-(-6) - \sqrt{64}}{2*1} = -1[/tex]
Since time is a positive measure, it will take 6 seconds for the rock to hit the ocean, and the answer is 7.
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Answer:
they all go straight across
Step-by-step explanation:
Answer:
Go across from each
Step-by-step explanation:
Which of the following describes volume? I. the amount of frosting on a cake II. the amount of space in a sock drawer III. the distance between two cities IV. the amount of fabric needed to cover a couch cushion
A. II
B. III
C. IV
D. I
Answer:2
Step-by-step explanation:
4
Which of the following is a function?
А
B
C
D
Answer:
B)
Step-by-step explanation:
A function is when every input has one output.
Easiest way is to do the "vertical line test" and "horizonal line test."
Basically you draw a vertical line and a horizontal line.
If either line passes through more than one point, then it is not a function.
The only one that passes them is B, the line.
Answer:
B
Step-by-step explanation:
A function is when every input has one output.
Easiest way is to do the "vertical line test" and "horizonal line test."
Basically you draw a vertical line and a horizontal line.
If either line passes through more than one point, then it is not a function.
The only one that passes them is B, the line.
The number line is 0 to 1 true or false 2/8 is close to 0
Answer:
True
Step-by-step explanation:
from the scale 0-1, 2/8 is closer to 0 because you round 2 down to 0, which gives you 0.
Please help, I’ve looked everywhere and haven’t found any answers!
Answer:
m = 4 + (2n)/(3)
Step-by-step explanation:
Move all terms that contain m to the right side and solve it.
Find cos (P)
Q
74
70
P
24
R
A.
37
12
В.
35
37
C.
12
Answer:
cos P = 71.09
Step-by-step explanation:
cos = [tex]\frac{adajcent}{hypotenuse}[/tex]
cos P = [tex]\frac{24}{74}[/tex]
cos P = 0.324
cos-1 of 0.324 is 71.09
cos P = 71.09
Stuck on this problem, can't find 3x
Answer:
x equals 10, angle measure is 30°
Step-by-step explanation:
By using the Vertical Angles Theorem which states that opposite angles formed by 2 intersecting lines are congruent we can find that the measure of the angle with 3x is equal to the measure of it's opposite angle or 30°. Using this we can make an equation that can find us our answer.
3x = 30
Divide both sides by 3
3x/3 = 30/3
x = 10
MADD (Mother's Against Drunk Drivers) wishes to estimate the proportion of adult drivers that have run at least one red light in the last month. A poll is conducted on a simple random sample of adult drivers and it is found that out of 1251 adult drivers, 641 of them have run at least one red light in the last month. You will be finding a 90% confidence interval for the fraction of adult drivers that run at least one red light in the last month.
Check that the normality assumptions are met?
Interpret the confidence interval obtained.
Answer:
Normality assumptions are met.
The 90% confidence interval for the proportion of adult drivers that run at least one red light in the last month is (0.4892, 0.5356). The interpretation is that we are 90% sure that the true proportion of all adult drivers than ran at least one red light in the last month is between these bounds.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
Out of 1251 adult drivers, 641 of them have run at least one red light in the last month.
This means that [tex]n = 1251, \pi = \frac{641}{1251} = 0.5124[/tex]
Normality assumptions:
We need that: [tex]n\pi[/tex] and [tex]n(1-\pi)[/tex] are 10 or greater. So
[tex]n\pi = 1251*0.5124 = 641[/tex]
[tex]n(1-\pi) = 1251*0.4876 = 610[/tex]
So the normality assumptions are met.
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5124 - 1.645\sqrt{\frac{0.5124*0.4876}{1251}} = 0.4892[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5124 + 1.645\sqrt{\frac{0.5124*0.4876}{1251}} = 0.5356[/tex]
The 90% confidence interval for the proportion of adult drivers that run at least one red light in the last month is (0.4892, 0.5356). The interpretation is that we are 90% sure that the true proportion of all adult drivers than ran at least one red light in the last month is between these bounds.
At Central Theatre, the cost of a matinee movie is under $5.50. The cost of a
popcorn is exactly $2.25. Write an inequality for the possible total cost, c, of a
movie and popcorn. Show your work.
Answer:
5.50 + 2.25 ≥ c
Step-by-step explanation
Movie = 5.50
Popcorn = 2.25
C = The total cost
5.50 + 2.25 = C
If two objects travel through space along two different curves, it's often important to know whether they will collide. (Will a missile hit its moving target? Will two aircraft collide?) The curves might intersect, but we need to know whether the objects are in the same position at the same time. Suppose the trajectories of two particles are given by the vector functions for t 0. Do the particles collide? If they collide find t. If not enter NONE.
r1(t) = t^2, 8t − 15, t^2
r2(t) = 11t − 30, t^2, 13t − 40
t=
Answer:
Step-by-step explanation:
[tex]r_1(t) = < t^2 , 8t-15,t^2> \\ \\ r_2(t) = < 11t-30, \ t^2 , \ 13t-40> \\ \\ at \ r_1 = r_2 \\ \\ t^2 = 11t - 30 , \ \ \ \ \ \ \ \ \ \ \ \ 8t - 15 = t^2 , \ \ \ \ \ \ \ \ \ t^2 = 13t -40 \\ \\ t^2 - 11t + 30\ \ \ \ \ \ \ \ \ \ \ \ t^2 -8t + 15 , \ \ \ \ \ \ \ \ \ \ \ \ t^2 -13t + 40 \\ \\ t^2 -8t-3t + 30=0 \ \ \ \ \ \ t^2 - 2t -4t + 15=0 \ \ \ \ \ \ t^2 - 1t - 13t + 40 =0[/tex]
[tex](t-6)(t-5) \ \ \ \ \ \ \ \ \ \ \ (t-5)(t-3) \ \ \ \ \ \ \ \ \ \ \ (t-5)(t-8)[/tex]
[tex]\mathbf{The \ common \ value \ of \ t \ = \ 5}[/tex]
Can some one please help me with this math assignment . I would be really grateful
9
On a field trip, there are 3 adults for every 45 students. Which graph models a relationship with
the same unit rate?
А
с
101
9
10
9
8
7
7
6
5
4
b
6.
5
4
3
2
3
2
1
0
30
60
90 120 150
30
60 90 120 156
B
D
10T
9
8
10
9
6
5
Answer:
I believe the answer is C
What is the total surface of the pyramid in square centimeters? A: 17.5 B:70 C:140 D:35
Answer:
C:140
Step-by-step explanation:
because 7 x 5 in the tiangle.
PLEASE HELP
determine the intercepts of the line
x intercept (__ , __)
y intercept (__ , __)
Answer:
i think y=2 and x=-7
Step-by-step explanation:
Maurice Luken deposited $3,021 in a savings account that paid 5.5 percent interest
compounded daily. How much interest did he earn in 31 days?
9514 1404 393
Answer:
$14.14
Step-by-step explanation:
The amount of interest earned is ...
I = P((1 +r/365)^n -1) . . . . interest on principal P at annual rate r compounded daily for n days
I = 3021(1 +0.055/365)^31 -1) ≈ 14.14
$14.14 in interest is earned in 31 days.
The square pyramid has a base area of 144 square centimeters and a height of 12 centimeters. Find the volume.
Step-by-step explanation:
the answer is 576 cubic centimetre.
Answer:
Its 576 cubic centimeters
Step-by-step explanation:
POV: you procrasiant a lot and dont pay attention on online school and ur failing ur classes, so now ur on brainly, just me?
also someone pls answer my other question will make brainliest!
Answer:
its true i cant pay attention in class cuz its boring but im
not failing it thank god
Answer:
sameeee but im currently not failing, lets hope it stays like that ;-;
Step-by-step explanation:
im smart
To compare the dry braking distances from 30 to 0 miles per hour for two makes of automobiles, a safety engineer conducts braking tests for 35models of Make A and 35 models of Make B. The mean braking distance for Make A is 41feet. Assume the population standard deviation is 4.6 feet.The mean braking distance for Make B is 45feet. Assume the population standard deviation is 4.3 feet.At alphaequals0.10,can the engineer support the claim that the mean braking distances are different for the two makes of automobiles
Answer:
There is sufficient evidence to support the claim.
Step-by-step explanation:
Given
[tex]\alpha = 0.10[/tex]
Make A
[tex]\bar x_1 = 41[/tex]
[tex]\sigma_1= 4.6[/tex]
[tex]n = 35[/tex]
Make B
[tex]\bar x_2 = 45[/tex]
[tex]\sigma_2 = 4.3[/tex]
[tex]n = 35[/tex]
First, we state the null and alternate hypothesis
[tex]H_0 : \mu_1 = \mu_2[/tex]
[tex]H_1 : \mu_1 \ne \mu_2[/tex]
Next, calculate test statistic:
[tex]z = \frac{(\bar x_1 - \bar x_2)-(\mu_1 - \mu_2)}{\sqrt{\frac{\sigma_1^2}{n_1}+\frac{\sigma_2^2}{n_2}}}[/tex]
[tex]z = \frac{(41- 45)-0}{\sqrt{\frac{4.6^2}{35}+\frac{4.3^2}{35}}}[/tex]
[tex]z = \frac{-4}{\sqrt{0.6046+0.5283}}[/tex]
[tex]z = \frac{-4}{\sqrt{1.1329}}[/tex]
[tex]z = \frac{-4}{1.0643}[/tex]
[tex]z = -3.7583[/tex]
The critical value at [tex]\alpha = 0.10[/tex] is: [tex]\±1.282[/tex]
[tex]-3.7583 < -1.282[/tex]
So, we reject [tex]H_0[/tex]
This implies that; there is sufficient evidence to support the claim.
tell what place the digit is in for the following number 14,632.708
4
0
7
Answer:
4 is in the one thousands place. The 0 is in the hundredths place. The 7 is in the tenths place.
What is 5x5+34-10 pls need help
which set of measurements would NOT creat a triangle?
A) 3in,8in,6in
B) 14in,6in,20in
C)11in,12in,22in
D)9in,8in,16in
Combine like terms
x + 10x-30= -8
Answer: x=2
Isolate the variable by dividing each side by the factors that don't contain variables.
True or False: x is the same/equal to 1x
Answer:
Yes
Step-by-step explanation:
Because you're multiplying by 1 so it stays the same value
Can someone please help meeee I’m desperateeee
Answer:
Step-by-step explanation:
1)(-3x+10)(50-x)=180
-4x+60=180
-4x=120
x=-30
2)6x+2+2x=90
8x=88
x=11
larger angle: 68°
3) a=3x°
4)(7x-5)=-2x+22
9x=27
x=3
DBE=16°
5)(x-39)=2x-59)
x=20
What is the answer to
2x squared?
Answer:
it’s just 2x^2
it’s not factorable
A researcher found that 55% of families in the United States have one child under the age of 21, 22% have two children under the age of 21, 15% have three children under the age of 21, 5% have 4 children under the age of 21and 3% have 5 or more children under the age of 21. If a family is selected at random, what is the probability the family has at least 3 children under the age of 21? (Express your answer as a percent, Please include the % symbol.)
Answer:
23% probability the family has at least 3 children under the age of 21.
Step-by-step explanation:
If a family is selected at random, what is the probability the family has at least 3 children under the age of 21?
15% have three children under the age of 21
5% have 4 children under the age of 21
3% have 5 or more children under the age of 21.
So:
15% + 5% + 3% = 23%
23% probability the family has at least 3 children under the age of 21.
Alice has $90 to spend on
new clothes. She wants to buy
some shirts for $20 each. If
she has a coupon for $10 off
her total purchase, how many
shirts can she buy?
Answer:
5
step by step explanation:
if she gets $10 off of her purchase that means she would have a little extra money to another shirt
For each ordered pair determine if it is a solution to 7x+5y=9
(-4,-3)
(-3,6)
(5,0)
(2,-1)