# Posts by Don

Total # Posts: 588

Math
Thats correct so far.

Physics
Part a) Assume that downward is positive for this problem. V=V_o + g*t V_o = 2.13 g=9.8 t=4.38 V=2.13 + (9.8*4.38) V = 45.1 m/s part b) x= V_o*t + (1/2)*g*t^2 x=(2.13*4.38)+(1/2)*9.81*4.38^2 x=103.43 note that the helicopter is going down at: x1=2.13*4.38 = 9.33 X = x - x1 X...

algebra
Wait Mr. Reiny, I think there is a typo. 3x^2+x-2=0 So there should be two roots x= -1 x = 2/3 And since the question is asking for "integer", I guess only -1 works since 2/3 is a fraction which is not an integer.

algebra
Equation: 3x^2 + 1*x = 2 I don't think that equation will factor, so you're going to have to use the quadratic formula to find what x is. 3x^2 + x - 2 = 0 I got x to be -1 and 2/3 Let me know if you got the same from applying the quadratic formula

physics
So it takes the blade .398s to move 90 degrees a full circle is 360 degrees 360/90 = 4 So time it takes to move around whole circle: T = .398*4 = 1.59s Velocity = Distance / time Distance in this case is the circumference of circle: C=2*pi*r where r is radius so C = 2*pi*(.352...

Algebra
First find the slope of the line through those coordinates. Slope formula: m = (y2-y1)/(x2-x1) m=(7-3)/(4-5) m=4/-1 m=-4 So the slope is -4 Now use the point slope formula: y-y1=m(x-x1) y-3 = -4(x-5) y-3=-4x+20 y=-4x+23 You will get the same result if you use the other ...

math
First you have to find how much each chairs cost 560/16 = 35 So each chair cost \$35. 35 * 24= 840

PHYSICS
Part a) Moment of Ineria for a sphere (formula is different depending on the shape: I = (2/5)*m*r^2 I = (2/5)*14.5*.120^2 = .0835 Angular momentum = I * angular velocity .0835 * 6.15 = .51 kgm^2/s Part B) Kinetic energy = (1/2)*.0835*(6.15)^2 = 1.579 J

physics
Is that the whole question? I'm guessing to break that force up into x and y components Fx = 52.8cos18 Fy = 52.8sin18

Math - Please Help Check My Answer
The answer the student has is correct. c = -1/13 The correct answer is A The answer is negative.

physics
D = speed * time just make sure to convert your units. Give it a try!

guidance
Key word: NOT B.

Physics
oops tan^-1(368.85/190.5) = 62.68

Physics
hmm.. Vx= 220cos30 = 190.5 Vy = 110 s=-Vy*t + (1/2)*a*t^2 2800 = -110*t + (1/2)*(9.81)*t^2 use quadratic equation to solve for t t=37.6s v=g*t v=9.81 * 37.6 v=368.85 tan^-1(v/vx) tan^-1(368.85/110) = 73.39 See if that's correct..

physics
a=(vf-vi)/t vf=73.6 * (1/3600)*1609.34 = 32.9 m/s vi = 0 (at rest) a=32.9/7.68 = 4.28 m/s^2

Precalculus
a) radius of a circle a=pi*r^2 to write this as a function of r a("r")=pi*r^2 pug in what r is to find what a equals b) r(t) = 2.2t where you plug in what your t is to give you r try using what I gave you for part a and b to find out the rest. Post if you have ...

Math
weekly revenue rate = -500*1 Price decrease rate = -.45 Marginal Revenue = (-500*1)(-.45) = 225

Math
This type of problem involves a lot of trig idenities, I just looked them up.. Lets look at the LHS: csc^2(x)= 1/sin^2(x) cos^2(x) = 1-sin^2(x) Now we can say: csc^2(x)*cos^2(x) = (1-sin^2(x))/sin^2(x) now lets look at the RHS: csc^2(x) = 1/sin^2(x) and we can change that 1 to...

physics
Note that "r" and "g" cancels out when you put the coefficient of friction equal to each other for car A and car B

physics
Coefficient of friction is: u=v^2/(r*g) now lets apply this formula to the problem Set Car A = Car B and you get V_a^2/V_b^2 = u_a/u_b v_b=v_a*sqrt(u_b/u_a) (13.8)*sqrt(.843/.333) = 21.95 m/s

TYPO
Made a small typo.. Answer is y+9 =(7/8)*(x+2)

Jay
Yeah

Jay
Point slope form is y-y1 = m(x-x1) y-(-9) = (2/7)*(x-(-2)) y+9 =(2/7)*(x+2)

Algebra
You gotta make the graph, use those points.

Algebra
x coordinate can be all negative # and zero y can only be all negative # so make a t chart x=0,-1,-2,-3,-4,-5……. y=-1,-2,-3,-4,-5,-6….

physics
Was velocity given in the figure?

MISTAKE
Oops, I made a mistake.. (4500*.04)+(.1*x)=1000

algebra
Set this up as an equation. (4500*.1)+(.1*x)=1000 solve for x to get your answer.

Algebra
Well, rate of change = slope deltaY/deltX = slope deltaY = (y2-y1) deltaX =(x2-x1) For the year 1990-1992: deltaY = (55-52) = 3 deltaX =(1992-1990) = 2 3/2 = 1.5=slope So basically, you have to pick 2 years where deltaY > 3 deltaY <= 2 so the only years that meet those ...

physics
Sorry, I made an error… Vector A has both an x and y component: Fx=10cos25=9.06 Fy=10sin25=4.266 Magnitude of A = sqrt(9.06^2+4.266^2) = 10.0141 Vector B only has x components: Fx=8 Magnitude of B = 8 10.0141*8 = 80.112

physics
If I'm reading this correctly, the question wants you to find the magnitude of vector A and then multiply it to magnitude of vector B. If that's the case then… Vector A has both an x and y component: Fx=10cos25=9.06 Fy=10sin25=4.266 Magnitude of A = sqrt(9.06^2+4....

Intermediate Algebra
find the average of hours of homework completion. (6+9)/2 = 7.5 hours

Trigonometry
sin^-1(12/13) = 67.38 180-67.39 = 112.62 = A sin^-1(-7/25) = -16.26 = B Tan ( A - B) = ??? I think that's how you approach it.. someone verify please?

math
4+x+2=9

math
1/(8000*450) = 2.77*10^-7

math
Wait it's 2x+5=-c

math
I agree with your answer.

Algebra 2 (PLEASE, HELP ME!)
I think for part C: match a t chart for x and y for the light weight, x can be anything bigger than 200 and lower than 230 so x can be 200 all the way to 229 Now do the same for the heavy weight class then plot them. for part D: It's asking at what point the lines ...

algebra
Hmm.. lets start with the polynomial (x+13)(-x+12) = -x^2 - x + 156 part b) The discriminant is everything inside the square root of the quadratic formula 150= -x^2 - x + 156 -x^2-x+6 a=1 b=-1 c=6 so: b^2-4*a*c is the discriminant -1^2 - 4*-1* 6 = 25 and 25 > 0 part c) Just...

Physics
Kinetic energy + Potential Energy (1/2) *m*vf^2 + (1/2)*m*vi^2 = mgh m=mass but we we really don't need the mass to figure this problem out since we can factor it out of the equation Now isolate the vf vf = sqrt(2*g*h - vi^2) g=9.81 h=30 vi=45 vf=sqrt(2*9.81*30 - 45^2) vf=...

Math
97 rounded to nearest ten gives 100 97 rounded to nearest hundred gives 100 118 rounded to nearest ten gives 120 118 rounded to nearest hunted gives 100 5 rounds to nearest ten is 10 179 rounded to nearest ten gives 180 179 rounded to nearest hundred gives 200 5091 rounded to...

physics
if you still need this i'll take a shot at it.. I drew this a free body diagram of this You should get a triangle when you do this where 228 is your hypothenuse is 228 so the formula to to find the missing side is c^2=a^2+c^2 where c=228 and a=50 so the missing side b = ...

math
x=semir y=sarah z=sung semir sold 3 times as many meals as sarah x=3*y sung sold 2 more meals than sarah. z=2+y y=y so 3*y + y + (2+y) = meals sold you can simplify more 3y+2y+2

Math
I set up as an equation: (1/2)*x*3 = 324 solving for x will give you the total cost of the three pairs of shoes x=208 324-216 = 108 hand bag is \$108

Pre-Cal
It mean's that the college of nursing students doesn't have to take statistics

physics
F=ma F=Force m=mass a=acceration F/m = a 3.25/3.8 = .855m/s^2 a=.855 m/s^2 now we have to find velocity at given time a*t=v .855*16.5 = 14.11 m/s now momentum formula p=m*v p=momentum m=mass v=velocity p=3.8*14.11 = 53.616 Ns Someone check my work.

math
Or if it's written (7 * 4) - (4/2) = 26 then its correct.. Actually, I think this post is the one you should look at

math
(7 x 4 - 4)/2 = 26 PEMDAS Do calculations in the parenthesis first: 24/2 = 26 Do you think that's true or false?

Math
C probably.

Algebra 2
should get a diagonal line

Algebra 2
Make a t chart and plug in an initial x to get your y to get your points then graph. for example: pick 1 for x as your starting y=|1|/2 - 3/4 y=-1/4 so first points are x=1 y=-1/4 x=2 y=??? x=3 y=??? so on..

Math
surface arena of a cone: A=pi*r(r+sqrt(h^2+r^2)) where r=radius Given: A= 258 cm^2 r=4 cm find h 258=(3.14*4)(4+sqrt(h^2+4^2)) 258=12.56(4+sqrt(h^2+16)) 258/12.56 = 4+sqrt(h^2+16) 16.54 = sqrt(h^2+16) square both sides 274.233 = h^2 + 16 258.233 = h^2 h=16.0696

pre cal
circumference of a circle: C=2*pi*r where r=radius=27/2=13.5ft pi=3.14 C=84.78 It's making 2 rotations every 2 seconds or in other words, 1 rotation every 1 second. note its asking for mph: 1hour=3600 12inch=1foot 1mile=5280 Formula to solve this: (n*C*3600)/(12*5280) ...

math
There are 75 employees, and they all get 2 weeks off per year, so total weeks off for everyone is: 75*2 = 150 weeks Now: 1 year = 52.18 weeks The total weeks that all 75 employees work without the 2 week vacation is: 75*52.18 = 3913.5 Total week - vacation week=net working ...

MATH 101
Can't really factor anything out of this. (7 a - 3 b) (8 a + 9 b) If you FOIL: you get 56a^2+39ab-7b^2 I just kind of did trial and error.

Math
If you tried 1 2 3 4 and took the product you would get 24 which doesn't equal one of the above numbers, so this combination wouldn't be correct.

Math
Take a look at 0,1,2,3 Those are 4 consecutive numbers. Now lets take the product of them: 0 * 1 * 2 * 3 = 0 As you can see, it's equal to one of the integers which is 0 So that meets the requirement. From those set of numbers, 3 is the largest.

Algebra
Hmm.. Let's break this down with what is given. There is a total of 1065.95 total. Mary has 122 in the cash register initially. So subtract 1065.95 - 122 = 943.95 943.95 is the total items she sold including tax Let's Figure out that amount excluding the tax, which is ...

Math
x<= 2100-300p 600 <= 2100 -300p p<= 5

Algebra 2
ah okay, well it's really basic algebra then. Just isolate the h h=(3v)/(pi*r^2)

Algebra 2
So…. what's given and what does it ask you to solve for?

Math
A = 1, otherwise the product would have 5 digits. D = 9 because A = 1. B = 0 or 1, otherwise the product would have 5 digits. If B = 1, then C = 0, otherwise the product would have 5 digits. But 1109 * 9 = 9981, which isn't right. So B = 0. Then 9*D = 9*9 = 81, so 8 + 9*C ...

sci207
LOL, this is a funny question.

Algebra
Yes. You are correct. y=3x plug 1000 into x 3 * 1000 = 3000

engineering science N4
I feel like the weight of the steel block has to be given in order to solve this problem…

maths
I set this up as a polynomial x^2-64x+960 factor this (x - 40)(x-24) where you it's roots to be 40 and 24 so 40 + 24 = 64 40 * 24 = 960

CHEMISTRY
First find molar mass of C6H12O6: I found it to be 180.1566 g/mol now find the ratio of moles 5.85/180.1566 = .0325mol Molality of C6H12O6: (.0325*1000)/255 = .127 note: the value 1000 is from the density of water which is 1.00g/mL So freezing point: delta_T = -k_f * m k_f = 1...

physics
yeah you are right, ignore my post.

physics
Final Velocity of 2.2kg ball: Vf = (V_i *(m1-m2) + (2m2*v_i2)/(m1+m2) v_i =1.27 m1=2.20 m2=7.2 v_i2 = 0 (because it was a rest initially) Vf=(1.27*(2.2-7.2)+(2*7.2*0)/(1.27+7.2)) =-6.35 For final Velocity of 2nd object: Vf = (V_i2 *(m2-m1) + (2m1*v_i/(m1+m2) Vf=(0*(7.2-2.2)+(2...

Science quick question urgent check my answer
Spores form part of the life cycles of many plants, algae, fungi and protozoa. In bacteria, spores are not part of a sexual cycle but are resistant structures used for survival under unfavourable conditions. --Wikipedia

Math
The college president asks the statistics teacher to estimate the average age of the students at their college. How large a sample is necessary? The statistics teacher decides the estimate should be accurate within half year and be 92% confident. From a previous study, the ...

math
you download 12 new songs to your mp3 player. then you delete 5 old songs.. write each amount as an integer?

hindi
What is the question

Math
What do I do next after that?

Math
but i don't get the first one

Math
Simplify the following expressions by using trigonometric form and De Moivre's theorem a. (√3-i)^4 b. (-4+4i√3)^5 c.(2+3i)^4 d. (4-i)^6

algebra
A three quarter inch wire has 12 ohms resistance. How much resistance has the same length of half-inch wire, if resistance varies inversely as the square of the diameter?

English
What is a metaphor for a deep voice?

Math homework help
Check out the polar coordinate pairs that label the same point. Several pairs may be possible. A) (2, 2pi/3) B) (2, -pi/3) C) (-3, pi) D) (2, 7pi/3) E) (3,0) F) (-3,0) G) (-2, -pi/3) H) -3, 2pi)

math
An investor in the 28 percent tax bracket is trying to decide which of two bonds to select: one is a 5.5 percent U. S. Treasury bond selling at par; the other is a municipal bond with a 4.25 percent coupon, which is also selling

Math
tum batao

Algebra 1
2+11b=8b+15

DISCRETE MATHS
Prove that if n is an odd positive integer, then 1 ≡ n2 (mod 4).

DISCRETE MATHS
Use the Euclidean Algorithm to find gcd(112,15)

DISCRETE MATHS
What is the cardinality of this set? {p, {p}, {p, {p}}} my answer is 1. is it right?

finance
12.6% is the wrong answer. Try 8.5%

pre-calculus
Move point (3,50 degrees) according to the following symmetries (keep positive) a. symmetrical to the origin b. symmetrical to theta=0 degrees c. symmetrical to theta= 90 degrees

stats please help ASAP!!!
A. The GPAs of all 5540 students enrolled at a University have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29. Let x be the mean GPA of a random sample of 48 students selected from this University. Find the mean and standard deviation...

MATHS STATISTICS(PLEASE HELP ANYONE!!
B. A soft-drink vending machine is supposed to pour 8 ounces of the drink into a paper cup. However, the actual amount poured into a cup varies. The amount poured into a cup follows a normal distribution with a mean that can be set to any desired amount by adjusting the ...

MATHS STATISTICS
B. A soft-drink vending machine is supposed to pour 8 ounces of the drink into a paper cup. However, the actual amount poured into a cup varies. The amount poured into a cup follows a normal distribution with a mean that can be set to any desired amount by adjusting the ...

MATHS STATISTICS
A. According to an estimate, 50% of the people in the United States have atleast one credit card. If a random sample of 30 persons is selected, what is the probability that 19 of them has atleast one credit card? PLIZ REALLY NEED HELP!! THANKS VERY MUCH..

linear algebra
solve using gauss jordan 10y − 4z + w = 1 x + 4y − z + w = 2 3x + 2y + z + 2w = 5 −2x − 8y + 2z − 2w = −4 x − 6y + 3z = 1

Math
The local dinner offers a meal combination consisting of an appetizer, two soups, four main courses, and five desserts. Your diet retricts you to choosing between a dessert and an appetizer. (You cannot have both). Given this restriction, how many three-course meals are possible?

mathURGENT!!!!!!!!!!
if 4^(x)-4^(x-1)=24 what is the value of (2x)^x? please answer and explain step by step how u got it... PLEASE?????

mathURGENT!!!!!!!
if (4^x)-(4^x-1)=24 what is the value of (2x)^x? please answer and explain step by step how u got it... PLEASE?????

Physics
A loop of wire has the shape shown in the drawing. The top part of the wire is bent into a semicircle of radius r = 0.12 m. The normal to the plane of the loop is parallel to a constant magnetic field ( = 0°) of magnitude 0.85 T. What is the change ÄÖ in the ...

Physics
In 1996, NASA performed an experiment called the Tethered Satellite experiment. In this experiment a 2.20 104-m length of wire was let out by the space shuttle Atlantis to generate a motional emf. The shuttle had an orbital speed of 7.50 103 m/s, and the magnitude of the earth...

Physics
A positively charged particle of mass 5.60 10-8 kg is traveling due east with a speed of 60 m/s and enters a 0.49-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 1.20 10-3 s, at which time it leaves the field heading due south. All ...

Physics
A positively charged particle of mass 5.60 10-8 kg is traveling due east with a speed of 60 m/s and enters a 0.49-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 1.20 10-3 s, at which time it leaves the field heading due south. All ...

Physics
A positively charged particle of mass 5.60 10-8 kg is traveling due east with a speed of 60 m/s and enters a 0.49-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 1.20 10-3 s, at which time it leaves the field heading due south. All ...

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