# 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 ...