Thursday
October 23, 2014

Posts by Damon


Total # Posts: 19,012

PHYSICS
LOL, again ? R = A V = L^2 L/T P = F/A = m L/T^2 / L^2 P = m L/ (T^2L^2) m = rho L^3 P = rho L^3 /(T^2 L) P = rho L^2/T^2 = rho v^2 4 by the way this does not give us the sign and rho is M/L^3 but is constant in the usual incompressible fluid problem
September 21, 2014

Physics I
v = Vi + a t here v = Vi - 9.81 t
September 21, 2014

Physics I
our acceleration is 9.81 DOWN, negative so our UP speed decreases g = -9.81 m/s^2 gravity does not push UP no matter if you are going up or down
September 21, 2014

Physics I
aaarrrggghhhh !!!! g is g is g is g = -9.81 m/s^2 so d when you throw a ball up, its speed up decreases until it stops ! The acceleration is 9.81 down until it comes back down and hits the ground.
September 21, 2014

Physics
u = 15 forever Vi = -20 h = Hi + Vi t + (1/2) a t^2 0 = Hi - 20 t - 4.9 t^2 but t = 4 so solve for Hi, initial height in 4 seconds at 15 goes 60 meters where is the basket at 4 seconds? h basket = Hi - 80 d = sqrt (60^2 + h basket^2)
September 21, 2014

physics
u = 22 cos 53.6 forever Vi = 22 sin 53.6 v = Vi - 9.8 t at top v = 0 0 = 22 sin 53.6 - 9.8 t solve for t, time to top h = 0 + Vi t - 4.9 t^2
September 21, 2014

physics
u = horizontal speed = 14.9 forever now vertical problem, simply drop from 7.05 m -h = -(1/2)gt^2 7.05 = 4.9 t^2 t = 1.2 seconds to fall how far horizontal in 1.2 seconds? x = 14.9 * 1.2
September 21, 2014

Algebra
average base = (3b-4+b)/2 = 2b-2 (2b-2)(b/2) = 210 b^2-b-210 = 0 (b-15)(b+14) = 0 b = 15 3b-4 = b/2 =
September 21, 2014

physics
t1 = 280/88 t2 = 210/75 all south so v average south = (280+210)/(t1+t2)
September 21, 2014

physics
change in x speed = 6.5 cos50-4.2cos34.5 change in y speed = -6.5 sin50-4.2sin34.5 ax = change in x speed/2 ay = change in y speed/2 a = sqrt (ax^2+ay^2) A = angle of a above horizontal tan A = ay/ax
September 21, 2014

physics
Vi = 0.43 v = Vi + a t v = 0.43 + 3(5)
September 21, 2014

physics
That is half a g for 5 minutes, way too gigantic but anyway v = Vi + a t here t = 5 * 60 = 300 seconds
September 21, 2014

physics
a = change in velocity / change in time = (6.5 -1.2)/25
September 21, 2014

statistics
http://davidmlane.com/hyperstat/z_table.html
September 21, 2014

physics
Boat 1 north velocity as seen from boat 2 = boat 1 north speed - boat 2 north speed 2.2 cos 47 = .745 - boat 2 north Boat 1 east as seen from boat 2 = boat 1 east - boat 2 east 2.2 sin 47 = 0 - boat 2 east
September 21, 2014

Math-HElP PLEASE??
2.25a + 1.75(300-a) = 613.5
September 21, 2014

physics
(1/2) m v^2 = m g h A.) v = sqrt (2 g h) = -sqrt (2*9.8*1.95) negative because down B.) (1/2)m v^2 = m g h or v = sqrt (2*9.8*1.87) positive because up) C.) change in velocity = (magnitude Part A + magnitude part Part B) divide that by .08 to get acceleration up D.) (1/2)(a ...
September 21, 2014

Math
is 111 prime? nope, 1,3, 37, 111 but 111 is certainly a factor of whatever our answer is 111*1 or 2 or 3 or whatever up to 9 so 3, 37 and what? How about 7 ? 777 = 7 * 3 * 37 10+37 = 47 sure enough
September 21, 2014

history
Shortage of supply over much of the Arabian Peninsula?
September 21, 2014

physics
U = 15 forever so d = u t now find t, time to fall 125 m 125 = 4.9 t^2 t = sqrt (125/4.9)
September 21, 2014

Chemistry
I agree with that.
September 21, 2014

Chemistry
You are welcome.
September 21, 2014

Chemistry
66.6 yards * 36 in/yard * 2.54 cm/in = L 12 in * 2.54 cm /in = w volume = w * L * t so 2.7 grams/cm^3 * w * L * t = 830 grams solve for t
September 21, 2014

physics
g is g is g
September 21, 2014

Algebra
(10 x + y) y = 2 + 4 x 13 + 3 (10 x + y) = (10 y + x) 13 + 30 x + 3 y = 10 y + x 29 x + 13 = 7 y = 7 (4x+2) 29 x + 13 = 28 x + 14 x = 1 then y = 4x+2 = 6 so 16
September 21, 2014

physics
1100.2 = 550 550 = (1/2) a t^2 550 = .5 * 1.2 * t^2 t = 30.3 seconds to go halfway (same for the second half) v = a t = 1.2 * 30.3 = 36.3 m/s 2 t = 60.6 seconds
September 21, 2014

physics
The vertical problem is the same for both Vi = 0 a = -9.8 until it stops Hi = 3.8 v = 0 + a t = -9.8 t h = 3.8 + 0 t - 4.9 t^2 when h = 0, the floor 4.9 t^2 = 3.8 t = .88 seconds in the air for both v at floor = -9.8 (.88) = - 8.62 m/s first ball straight down, x = 0 second ...
September 21, 2014

Physics
0 = 18 - 1.8 t t = 10 seconds to stop how far braking? d = av speed * time = 9*10 = 90 meters 125 - 90 = 35 meters before braking 35 meters / 18 meters/second = 1.94 seconds (best hurry)
September 21, 2014

science
P1 Vi = P2 V2 10(20) = P2(5) P2 = 40
September 21, 2014

Physics
surface area of sphere = 4 pi r^2 Watts/unit area at 15 m = 1.75/(4*pi*225)
September 21, 2014

Physics
d instructor = u t find t so you can find d, how far the instructor is from directly under when you drop. H = height H = (1/2) g t^2 t = sqrt (2 H/g) so d = u sqrt (2 H/g)
September 21, 2014

chemistry
125 (95-20)(4.184) Joules divide by 1000 to get kilojoules
September 20, 2014

physics
Calculate the total distance calculate the total time average v = distance/time
September 20, 2014

Math (Proving of Inequalities)
a^2-b^2 = (a+b)(a-b) (a+b) is + so if (a^2-b^2) is + then (a-b) must be +
September 20, 2014

5th grade Math
multiply (2/3) 3 = 2 cups (2/3) 1/2 = 1/3 t (2/3) 3/4 = 1/2 cup (2/3) 4 = 8/3 = 2 2/3 cup (2/3) 2 = 4/3 = 1 1/3 T
September 20, 2014

PHYSICS
G .35 Mb m/Ra^2 = G Mb m / Rb^2 .35 Mb/Mb = Ra^2/Rb^2 Ra/Rb = sqrt(.35)
September 20, 2014

physics
well in this case the result is exact, but in general there could be a constant of proportionality between the output and the input that we could not get from dimensional analysis for example Force on a plate of area A in a fluid of density rho in kg/meter^3 and speed v in L/T...
September 20, 2014

physics
R = v A (look at a drawing of what you have here) now the way you are supposed to do it v = L/T A = L^2 R = L^3/T = (L/T)L^2 so R = L A/T but L/T = v so R = v A
September 20, 2014

chemistry
2 mol of water --> 2*18 g 1 mol O2 --2*16 g (2*18/2*16) * 7.4 mg = 9*7.4/8 = 8.325 mg 7400 grams O2 ---> 8325 grams H2O ---> 8325 mL H2O or 8.325 liters
September 20, 2014

HELP IN SCIENCE ASAP!!
yes, yes
September 20, 2014

Science
You mean 10 m/s^2 I assume wow, 1 g for five minutes ? to the moon ? anyway 5 min = 300 s v = Vi + a t v = 0 + 10 (300) = 3000 meters/second
September 20, 2014

Science
yes, yes
September 20, 2014

Pre-Cal
y = +/- sqrt(1-x^2) if y is to be real, x must be x^2 </= 1 -1 < x < +1 similarly y ranges from -1 to + 1 so our function 2 x - 5y is maximum when x is 1 and y is -1 2 + 5 = 7
September 20, 2014

math
G = 1000 + 325 m E = 2500 + 325 m E always pays more than George by 1500
September 20, 2014

Algebra 2
1 and 2 fine 3. Evaluate (2.0 x 10^-7)/(8.0 x 10^-9). Write the answer in scientific notation. A: 0.25 x 10^2 but usually written 2.5 * 10^1 age is not a function of last name R = 75 - 3.5 d if d = 5 R = 75 - 17.5 = 57.5 dollars left in pocket
September 20, 2014

Physics
p Newton = m v p relativistic = m v /sqrt(1 = .75^2) so 100(p relativistic - p newton)/p rel here 1/sqrt(1-.75^2) = 1.512 so 100 ( 1.512 - 1)/1.512 = 33.9 %
September 20, 2014

Physics
E = m c^2 so m = E/c^2 E = 2*10^9 *21 * 7 *24 *3600 = 2.54*10^16 c = 3*10^8 m/s c^2 = 9 * 10^16 so m = 2.54 / 9 = .282 Kg = 282 grams
September 20, 2014

physics
You need to know two things: 1. how long does it take to fall 0.7 m 2. How fast is your horizontal velocity after falling 2.76 meters? Then distance = horizontal velocity * time to fall 0.7 meters = u t -------------------------- so, how long to fall 0.7 m? 0.7 = (1/2) g t^2 t...
September 20, 2014

History
French traders used the Red River to ship to New Orleans from the southern part of Oklahoma. I think they probably mean Red River although indeed the French fur traders also used the Arkansas.
September 19, 2014

History
None of the others happened in or around 1821 so I would say A
September 19, 2014

physics
original south = 9.75 cos 25 final south = 8.64 sin 35 original east = 9.75 sin 25 final east = -8.64 cos 35 south a component = (final south -original south)/ .179 east a component = (final east component - original east component) / .179 resultant mag of a = sqrt (south a^2...
September 19, 2014

Math
x axis intercepts at y = 0 (x-3)(x+1) = 0 x = 3 and x = -1 y axis intercepts where x = 0 y = -3
September 19, 2014

physics
Vi = 60.32 yes u = 85.3 cos 45 = 60.32 also but forever v = Vi + a t = 60.32 -9.81 t so at top when v = 0 t = 6.15 seconds coasting up h at top = Hi + Vi t -4.9 t^2 = 587 + 60.32 (6.15) - 4.9(6.15^2) = 773 meters high at 6.15 seconds when fall starts now it falls 773 = 4.9 t^2...
September 19, 2014

algebra - check my answer?
yes
September 19, 2014

Math
4(x-1)^2 + 3 (x-1) - 3 4(x^2-2x+1) + 3 x - 3 - 3 etc
September 19, 2014

Math
Yes, what Mia said :)
September 19, 2014

Math
about x axis? for any x is are there equal in magnitude + and - values of y? y ^2 = x+1 y = +/- sqrt (x+1) so yes but x must be >-1 about y axis? Nah, this is a parabola opening to the right with as vertex at (-1 , 0)
September 19, 2014

Math
Everything on the number line left of x = -2 including x = -2 so Big black dot on -2 arrow pointing left from there. I do not know what the number six has to do with the problem. B is the only one with all the values in our domain.
September 19, 2014

Math
w +(w+6) = 34 2 w + 6 = 34 2 w = 28 w = 14 ================== 5 a - 20 - 8 a = 55 -3 a = 75 a = 25 ====================== 6 n - 7 = 45 6 n = 52 n = 26/3 as you wrote it If you mean instead (2n-7)/3 = 15 then 2 n - 7 = 45 2 n = 52 n = 26
September 19, 2014

english
Illustrator
September 19, 2014

Math
You are welcome.
September 19, 2014

Math
n - 6 >/= 2 n >/= 8 agree
September 19, 2014

French
Everyone always says they are fine even if on the verge of death.
September 19, 2014

History
agree B turned out to be major.
September 19, 2014

Math
Yes
September 19, 2014

Math
g / - 5 < -18 if you multiply both sides by -5 you must reverse the direction of the arrow. g > + 90 C.
September 19, 2014

History
Negotiated relatively safe traffic through Indian lands from Missouri west
September 19, 2014

whoops, -1 not + 1 use Steve's answerr
dumb error
September 19, 2014

Pre-Calculus Questions
slope = (-3 - 3)/ (1+5) = -6/6 = -1 y = -x + b 3 = -1(-5) + b b = -2 y = -x - 2 =============================== x axis(0, -3) y axis where y = 0 x^2 - 2 x - 3 = 0 (x-3)(x+1) = 0 x = 3 or x = 1 so axis of symmetry and vertex at x = (1+3)/2 = 2 then y vertex = 4-4 - 3 = -3 so ...
September 19, 2014

History
Spanish gave up claim to Oregon territory
September 19, 2014

physics
v = 20 - 9.8 t v = 0 at top 9.8 t = 20 h = 20 t - 4.9 t^2 or m g h = (1/2) m v^2 h = (1/2)v^2/g
September 19, 2014

Mathematics
(1/2) 116 = 58 (1/2) 8 = 4 tan 58 = 4/h
September 19, 2014

math algebra word problems
Their speed is 1.5 + 1.2 = 2.7 miles a day
September 19, 2014

physics
period = 1/ frequency wavelength = period * speed so wavelength = speed / frequency Your textbook must have that !!!
September 18, 2014

Algebra
2 m^2 + 3 = m 2 m^2 - m + 3 = 0 m = [ 1 +/- sqrt (1 - 24) ]/ 4 = [ 1 +/- sqrt(-23) ]/4 complex conjugate pair.
September 18, 2014

science
....and you answered the question about how many cars and trucks incorrectly thereby confusing some other poor student.
September 18, 2014

science
Moreover we do not have the slightest idea what microscopes you might have in your school.
September 18, 2014

physics
lambda = distance = speed * time Time = period = 1/ frequency
September 18, 2014

Physics
a = change in velocity/change in time = (14 -0) / 10 2.) zero 3.) (1/2) m v^2 = m g h so v = sqrt (2 g h)
September 18, 2014

Math
If there were 6 trucks there would be 30 cars and 36 total, no good t + 5 t = 30 6 t = 30 t = 5 not 6
September 18, 2014

math
no x^n = x * x * x * x .......... n times
September 18, 2014

Math
balance = 4000 (1.05)^n geometric sequence a = 4000, r = 1.05 4000 4200 4410 etc
September 18, 2014

MATH WORD PROBLEM
180 = (3/2)x x = 360/3 = 120
September 18, 2014

physics
a = change in velocity / change in time and F = change in momentum / change in time (Newton #2, F = d/dt (m v) = m a if m is constant)
September 18, 2014

physics
a = (0-12)/.1 F * t = change in m v F * 0.1 = 60 (0-12)
September 18, 2014

Urgent Spanish Check
Well, for a bunch of Norte Americanos we are not doing too badly.
September 17, 2014

Urgent Spanish Check
hmmm, una clase is feminine but lo is masculine. La is feminine.
September 17, 2014

social studies check
I do not think he accomplished what he was hoping to accomplish. What he did accomplish was not his original objectives.
September 17, 2014

social studies check
Well, he did not find China. He ended up dead someplace west of the Mississippi. He did get a lot done and was the first European explorer in those parts, however the goals of his sponsors to find vast riches of gold, jewels and silver and find a route to the Orient were not ...
September 17, 2014

social studies check
I agree with D. It is hard to sustain a culture when everyone is dead.
September 17, 2014

Urgent Spanish Check
You are welcome.
September 17, 2014

Urgent Spanish Check
EL examen VERDE miS hermanas LOs
September 17, 2014

social studies check
I think the key word is PERMANENT. The woodland people were still in place when the Europeans arrived.
September 17, 2014

social studies check
THey did NOT want to form large plantations as in South Carolina !!
September 17, 2014

physics
Give ALL the units of resistivity. Then the problem solves itself as long as you know Area of circle = pi d^2/4 Resistance = resistivity * length/area
September 17, 2014

English
The only problem I have with these sentences is that they are extremely awkward. I would have said: I think I will be a good bow rower because I can balance the boat accurately. I think I will be good rowing in the middle of the boat because I am strong and can make the boat ...
September 17, 2014

Physics please help
slope of displacement versus time or dx/dt at any point is velocity v = integral of a dt if you were given the ACCELERATION ,a, you would need to do area, but you were not.
September 16, 2014

math
x y z 4 y z y>z 4 + y + z = 6 y + z = 2 since y>z y = 2 and z = 0 4 2 0
September 16, 2014

Pre-Calculus
a) so use -3 for x (-3)^2 + 9 = 9+9 = 18 b) now use -2 for x (-2)^2 + 9 = 4 + 9 = 13
September 16, 2014

Calculus I
dL = a Lo dT L = a Lo T + constant when T = 0, L = Lo so L = (a Lo) T + Lo To is y (or in this case L)axis intercept (a Lo) is slope
September 16, 2014

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