Tuesday

October 6, 2015
Total # Posts: 34,328

**Subj: Physics school: omar samatar secondary school**

v0 + 4a = 16 v0 + 10a = 28 a=2, v0=8 s(t) = s0+ 8t + t^2 Now you can figure the distance traveled during any interval.
*September 5, 2015*

**Math**

you have two 5-12-13 triangles. Since the two sides of 12 are joined as a single line, add up all the sides and subtract 12 twice for the interior sides. If that seems hard, just draw the figure, label the exposed sides, and do the math.
*September 5, 2015*

**Algebra I**

time = distance/speed You have the speed. Look up the distance and do the math.
*September 5, 2015*

**Algebra I**

no solutions, since that would mean that 4-b = 2-b 4 = 2
*September 5, 2015*

**UNAM**

it would be (.25*.015 + .125*.050)/(.015+.050) = 0.1538M
*September 5, 2015*

**physics**

since the ball went straight up, its has zero velocity at maximum height. So, what does that say about its momentum?
*September 5, 2015*

**numerical analysis**

well, you know that f(0) = -2 f(pi/2) = pi/2 So, start with those two values a1 = 0, b1=pi/2 so, c1 = pi/2-(pi/2)(pi/2-0)/(pi/2-(-2)) = 0.88 f(c1)=f(0.88) = 0.421 Since f(c1) > 0, a2 = a1, b2 = c1 = 0.421 I assume you can follow the method, as explained at https://en....
*September 5, 2015*

**Algebra**

Only true if a > 0. If a<0, then you have x < b/a or x<c.
*September 5, 2015*

**PRE CALCULUS**

In 8 years, the share price rose by 3.86, making the rate of change (slope) 3.86/8 = 0.4825 per year. So, since we started measuring at the $0.18 price, at t=5, the price p(t) is p-0.18 = 0.4825(t-5) Now you can find p(t) for other values of t. The other problem is worked in ...
*September 4, 2015*

**math**

If a line (-9,7) is marked by e which is a ratio of 1/4 then where is e on the line? My answer is -7
*September 4, 2015*

**Math - My Bad**

ignore my question. Ms Sue read it right
*September 4, 2015*

**math**

does each 4.5ft fence section have an and piece, or does the entire fence have two end pieces (one on each end)?
*September 4, 2015*

**math**

does 3x - 4x = x?
*September 4, 2015*

**Geometry**

In a Hexagon net for a 3 dimensional solid how many regions would there be? My answer is 8 the 6 sides and the top and bottom
*September 4, 2015*

**ALgebra**

take a look at the graph: .05v^2+1.20v <= 40 http://www.wolframalpha.com/input/?i=1.20v%2B.05v^2+%3C%3D+40 Though I don't see how the car will come to a stop.
*September 4, 2015*

**Counting Numbers**

zero. No square ends in 7. Only 1,4,5,6,9,0 Poke around a bit and you will quickly see why.
*September 4, 2015*

**MATH**

come on. adding a negative number is the same as subtracting a positive one. 6-4 = 6+(-4) Think of it as moving left and right on the number line. Subtracting 4 means moving left 4 places. So does adding -4.
*September 4, 2015*

**MATH**

you can think of it as (-3)(x+3) + (-2)(x+4)
*September 4, 2015*

**statistics**

Assuming I parsed the garbled English correctly, I agree that C was the correct choice. You really gotta work on your typing.
*September 4, 2015*

**Math**

0.42
*September 4, 2015*

**Algebra**

we have a winner!
*September 4, 2015*

**Algebra**

correct
*September 4, 2015*

**Algebra**

y=42x
*September 4, 2015*

**math**

Draw the diagram. It is clear that angle PQR is 90° in a 3-4-5 triangle. So, PR = 5km As for the direction, you can either figure the x- and y-coordinates of R, or note that angle QRP is arcsin(4/5), and add that to the diagram.
*September 4, 2015*

**Science**

Depends on how fast the car was moving at the start.
*September 4, 2015*

**math**

(15/2) / (9/4) = 15/2 * 4/9 = 10/3 = 3 1/3 So, 3 whole pieces.
*September 4, 2015*

**Math**

Do not expand first. So, let u = 5y+1. I'm sure you can solve u^2 + 5u + 6 = 0 (u+3)(u+2) = 0 u = -3 or -2 That means you now need to solve 5y+1 = -3 or 5y+1 = -2 No problem now, eh?
*September 4, 2015*

**Math- Algebra**

n-2 = c
*September 4, 2015*

**Math- Algebra - eh?**

help you do what?
*September 4, 2015*

**Algebra**

this is just the difference of two squares, so you have ((x+5)+(x-5))*((x+5)-(x-5)) = (2x)(10) = 20x If you expand it all out, you will easily see that everything but the x terms cancel out.
*September 4, 2015*

**calculus**

a = 24-15√t v = 24t-10t^(3/2) s = 12t^2 - 4t^(5/2) s=0 when 12-4√t = 0, or t=9 a(9) = 24-15√9 = -21
*September 4, 2015*

**Physics/trig**

consider what would happen if the plane were flying horizontally. The shadow would be moving exactly as fast as the plane. What if the plane were flying vertically? Shadow would not move. So, it's easy to see that if the plane is rising at an angle θ, the horizontal ...
*September 3, 2015*

**math**

no. Taking it as written, 3r+b/a+y = w 3r = w-y - b/a 3r = (wa-ya-b)/a r = (wa-ya-b)/(3a) If you meant (3r+b)/a + y = w (3r+b)/a = w-y 3r+b = aw-ay r = (aw-ay-b)/3 Maybe if you use some parentheses things will be clearer.
*September 3, 2015*

**algerbra**

1/4(x-h)=p+c x-h = 4(p+c) x = h + 4(p+c)
*September 3, 2015*

**math**

correct
*September 3, 2015*

**algebra**

W = 2L-10 So, 2(2L-10 + L) = 70 Now find L, then W.
*September 3, 2015*

**Math**

There are 54+92+12=158 total songs Of those, 54+92 = 146 are not classical. So, now what do you think?
*September 3, 2015*

**algebra**

I find the explanation of the problem quite unclear. Here is one guess: If you mean the volume of the material used, then if the outside radius is R, and the inside radius is r, the volume of material is 2π/3 (R^3-r^3) Assuming the outside radius is 40ft and the thickness...
*September 3, 2015*

**algebra**

3(a^2+b) - 4(a^2-b) 3a^2 + 3b - 4a^2 + 4b -a^2 + 7b
*September 3, 2015*

**Math**

If there were x 2-pointers and y 3-pointers, then we have x+y=8 2x+3y=18
*September 3, 2015*

**lee**

57632
*September 3, 2015*

**Math (Ratios)**

6/6 would be my choice
*September 3, 2015*

**algebra**

correct
*September 3, 2015*

**Pre-Calculus**

slope zero means y is constant. At x=0, y=9 so, the equation is y=9
*September 3, 2015*

**precalc**

D: all reals R: 2 no zeros or asymptotes not 1-1 continuous constant bounded If this one gave you trouble, you have a bumpy ride ahead!
*September 3, 2015*

**Math**

n is a perfect square means that there is a rational number k such that k*k = n Then k is the square root. The others are clearly false, since √5 is not rational √(3/5) is not rational Therefore, certainly not (d)
*September 3, 2015*

**algebra**

clearly the answer is A or B, since you want to find the time. Hint: since you want to find the time, it must be the dependent quantity. Hence, (A) is the answer.
*September 3, 2015*

**Algebra**

d-20 = 2(k-20)+16 d+k = 70 Now go for it.
*September 3, 2015*

**Precalc Math**

every repeating decimal of n digits, say, abc can be written as abc/999 where the denominator of n digits is 10^9-1 So, .23 = 23/99 5.23 = 5 23/99 = 518/99 You should have written 100x = 523.23... x = 5.23... 99x = 518 x = 518/99 If there are n repeating digits, multiply by 10^n
*September 3, 2015*

**Alg 2**

1B 5C 6C 12B
*September 3, 2015*

**math**

ok except for the last. √5 is irrational, so any rational multiple of it is also irrational. (A) (C) is the only imposible choice. Every real number is either rational or irrational, but cannot be both or neither.
*September 3, 2015*

**geometry**

the midpoint has coordinates (x,y) that are the average of the endpoints. So, (3+x)/2 = 5 (5+y)/2 = -11 Or, you can reason that 5 2 larger than 3, so the x-coordinate of v will be another 2 larger. Same for y.
*September 3, 2015*

**geometry**

the angle is bisected into two equal parts, so x-3 = 2x-13
*September 3, 2015*

**geometry**

google is your friend. For example, see http://www.mathsisfun.com/geometry/construct-linebisect.html
*September 3, 2015*

**cms**

.25(300) = .20(300+x) Or, since the concentration is being reduced by a factor of 4/5, the volume is increasing by a factor of 5/4. The additional volume is 1/4 of 300.
*September 3, 2015*

**Calculus (limits)**

look on the graph. Where you would find f(2), does the line approach the same value from both sides? If so, that value is the limit.
*September 3, 2015*

**Algebra**

7*14 + 170 = (7+2w)(14+2w) Now solve for w
*September 3, 2015*

**math**

better review the distributive property. associative would be (6a+2a)+8b = 6a+(2a+8b)
*September 3, 2015*

**mathematics**

The digits are x and x+1, so (10x + x+1) = 5/6 (10(x+1)+x) Now you can find x. Extra credit: How did I know which digit came first?
*September 3, 2015*

**Algebra 2**

5r+4 <= 5 5r <= 1 r <= 1/5 I assume you can graph that on the number line.
*September 3, 2015*

**sjpuc**

If the swimmer's speed is s and the water's speed is w, we have s+w = 60 s-w = 8 I think you can now find s and w, no?
*September 3, 2015*

**Algebra. Please check my answers**

4^5 means 4 to the 5th power, or 1024 I suspect you meant something else. -(12x-8y) means -1(12x-8y) so you must use the distributive rule: -(12x-8y) = (-1)(12x) + (-1)(-8y) = -12x+8y So, (C) Your answer simply ignored the outside minus sign. It is the same as +(12-8y)
*September 3, 2015*

**Algebra**

#1 ok #2 ok, since 6/(x+y) isn't in the list #3 nope. What does quotient mean?
*September 3, 2015*

**MATH**

what does nCr4 mean? Try writing things as C(n,r+2) etc to make the arguments clear.
*September 3, 2015*

**math**

better check again. The pieces are 1'3" 2"6" 4'12" 8'24" add them up. Or, using a geometric series, the total is 1.25(2^4-1) = 18.75
*September 3, 2015*

**physics**

clearly a = (12rad/s)/(3s) = 4 rad/s^2 As with linear motion, s = 1/2 at^2, so it traveled through 1/2 * 4 * 9 = 18 rad
*September 3, 2015*

**Math. Check my answers**

6D (distributive property) 12B |-8| = 8 and |-10| = 10. 8 < 10 The others are all ok.
*September 3, 2015*

**math**

The tens digit must be even, since the hundreds is 1/2 of it. with the ones digit greater, that leaves 128 or 245 I suspect a typo.
*September 3, 2015*

**Math**

In that case, you made a mistake b^2 = 0.0063^2 = 0.00003969 4ac = 4(.00013)(-4.7) = -0.002444 b^2-4ac = 0.00248369 √(b^2-4ac) = 0.04984 (-.0063+0.04984)/.00026 = 167.45 (-.0063-0.04984)/.00026 = -215.91
*September 3, 2015*

**math please help!!**

The depth at midline is 7.9+1.1 = 9.0 f(t) is at midline at t=0, so you want a sine function, not cosine, which starts at a max. So, f(t) = 9.0 ± 1.1 sin(π/2 t) I use ± because they don't say whether the water is rising or falling at t=0.
*September 3, 2015*

**calculus**

sine or cosine, since (sin x)" = -sin x (cos x)" = -cos x So, (D)
*September 3, 2015*

**Math**

24:36 = 2:3, so each bag must contain at least 2 candles and 3 bottles. Can you take it from there?
*September 3, 2015*

**Math**

express everything in terms of meters: (7m)(2m)(0.1m) = 1.4 m^3
*September 3, 2015*

**Algebra**

original dimensions are w and 4w 4w-18 = w+18 Now you can find w, and 4w.
*September 2, 2015*

**Math**

just add a and b If c is negative, adding it is the same as subtracting its absolute value a+b+c = a+b-|c| That is, adding a negative value is the same as subtracting an equal positive value.
*September 2, 2015*

**math**

30 and 90
*September 2, 2015*

**Math**

-15 < 25
*September 2, 2015*

**math redux**

see related questions below
*September 2, 2015*

**Math**

think about it. A smaller pulley has to turn faster to convey the same amount of rope. Two pulleys of radii r1 and r2 move the same amount of rope if their speeds s1 and s2 are such that r1 * s1 = r2 * s2 Now just plug in your numbers
*September 2, 2015*

**Math**

SN is very good at expressing large numbers in a succinct manner, without having to count all those digits.
*September 2, 2015*

**Algebra 2**

The radius is 68, so the center is at y=68+14=82 x^2 + (y-82)^2 = 68^2
*September 2, 2015*

**algebra**

because it can be written as 57/100, the ratio of two integers. Any terminating decimal can be written in this way, as a fraction with the denominator a power of 10.
*September 2, 2015*

**Math**

there is a vertical asymptote when the denominator is zero. Since x^2+8 is never zero, there is no asymptote. Trick question.
*September 2, 2015*

**math**

I would assume you just replace all the r's with 1, and all the s's with 5: 2(5^3)-4(1^2) = 2(125)-4(1) = 250-4 = 251 Just plug and chug. I assume the arithmetic does not cause problems...
*September 2, 2015*

**algebra**

100m/11s * 1mi/1609m * 3600s/hr = 20.3 mi/hr Just keep track of the units, and use the conversion factors that make them cancel out the way you want.
*September 2, 2015*

**help please with math thanks**

You sure use a lot of words. Try using these characters in the future. If you can't recall the alt-codes, you can always find them and copy/paste them. #1 a. 3 + 2 b. √19 + 7/2 c. 18/3 + 11/10000 Your answers look good. I would have chosen 2C, but maybe you have been...
*September 2, 2015*

**Algebraic word problem**

We have: f = 5p p = 2m f+2 + p+2 + m+2 = 58 5p+2 + p+2 + p/2+2 = 59 Hmmm. I don't get an integer answer. Inspect problem for typos, and double-check my math.
*September 2, 2015*

**math**

h+|-8| = 15 h+8 = 15 h = 7 Looks like you need to review your absolute value function.
*September 2, 2015*

**calculus**

what, you have forgotten your 1st and 2nd derivative checks? And geez, this is one of your basic trig functions. You already know where the max/min/inflections are, so it's easy to check your answers. y = cosx y' = -sinx y" = -cosx y'=0 at all multiples of &#...
*September 2, 2015*

**calculus**

you know that v = π r^2 h, so h = v/(πr^2) the area is a = 2πr(r+h) = 2πr(r + 11.3/(πr^2)) = 2πr^2 + 22.6/r for minimum area, da/dr=0, so da/dr = 4πr - 22.6/r^2 = (4πr^3-22.6)/r^2 da/dr=0 when 4r^3-22.6=0, or r=1.216 The diameter d = 2r.
*September 2, 2015*

**math**

If her average now is x, then her total points so far are 4x. So, we have (4x+70)/5 = x-4 x = 90
*September 2, 2015*

**trig**

since A+B+C=180, A=70° Now use the law of sines to find c: c/sinC = a/sinA c/sin48° = 18.2/sin70° c = 14.4
*September 2, 2015*

**Biology**

Of the following, which is the most likely consequence of a manufacturing plant dumping its chemical waste into a nearby stream? increased oxygen levels in the water decreased flow rate of the stream loss of a keystone species an algal bloom <- my answer My question is ...
*September 2, 2015*

**Math**

what about 33 and 44?
*September 2, 2015*

**PHYSICS**

the crumpling bumper absorbs some of the impact, transmitting less force to the riders inside the car.
*September 2, 2015*

**physics**

The mass m does not matter. It takes about 1 second to fall 5 meters (using g=10m/s^2). Since v = at, that means v = 10 m/s
*September 2, 2015*

**calculus**

Looks like (a) to me. Assuming no typo in the equation.
*September 2, 2015*

**Math**

why bother with that? If the area is given in yd^2, just give each side in yd. √520 = 22.8035... So, each side is about 22.8 yd Now, if they wanted the dimensions in feet, then you'd divide the area by 9, since each yard is 3 ft, but you would certainly not divide ...
*September 2, 2015*

**Math**

If B's speed is x, the A's speed is x+53 Since distance = speed*time, we have 4.25(x + x+53) = 4568.75
*September 2, 2015*