# Posts by Damon

Total # Posts: 31,636

physics
u = cop car speed v = perp car speed Ui = 40 Vi = 38 initial momentum = 1800 Ui + 1500 Vi = 1800(40) + 1500 (38) = 129,000 (same after) so 129,000 = 1800 u + 1500 v now Ke (1/2) 1800 (40)^2+ (1/2)(1500)(38)^2 = (1/2)(1800)(u^2) + (1/2)(1500)(v)^2 or 6(40)^2 + 5(38)^2 = 6 u^2...

Physics
east is positive 1515 E -1125(45) = 2640 V F = 2640*.75 = -1980 pounds so -1980 pounds = m a but m = 2640/g where g = 32.2 ft/s^2 so a = -(1980/2640)g = -.75 g = -24.15 ft/s^2 = dv/dt 0 = V-24.15 t so V =24.15 t 22.5 = V t -12.07 t^2 22.5 = 24.15 t^2 - 12.07 t^2 = 12.07 t^2 t...

Math
P = 0, never happens P = 1, always happens binomial probability P(n,r) = C(n,r) m^r (1-m)^(n-r) for exactly r = 1 for n = 2 C(2,1) = 2!/[1!(2-1)!] = 2 P(2,1)= 2 m^1 (1-m)^1 = 2 m(1-m) in other word yes-no or no-yes :) now for twice P(2,2) = 1 m^2 (m-1)^0 = m^2 which we all ...

PHYSICS
Ac = v^2/R 3.61 = v^2/225

Trig
hey think if m = 19 y=x^2-19x+4 and y=x^2-19x+9 then the second parabola is always 5 units above the first

Mathematics
https://www.jiskha.com/display.cgi?id=1509414055

Mathematics
I did, with the reservation that P = k d is actually wrong.

physics
First the vertical problem Vi = initial speed up = 52 sin 45 = 36.8 m/s H = 0 + Vi t - 4.9 t^2 0 = 0 +36.8 t - 4.9 t^2 t = 0 or 7.5 seconds so 7.5 seconds in air now horizontal problem u = 52 cos 45 = 36.8 m/s forever d = u t = 36.8 * 7.5

Physics
6.86 = m g - 1000 g V g = 9.81 m/s^2 6.86 = 9.81 (68) - 9810 V 9810 V = 660 V = 66/981 m^3 m = 68 so m/V = (68/66)981 = 1011 kg/m^3 =============================== In seawater volume of boy = 66/981 so mass of water displacedd submerged = 1029*66/981 = 69.2 kg BUT boy only has...

Science
That is basically wrong because you are ignoring the atmospheric pressure of the air above the water so the variation is NOT DIRECT p = k x but linear p = patmosphere + k x but if we ignore the physics and do it the way the math people want you to do it then P at 4.5 m = 125 *...

Math
Hey, to add or subtract fractions you need a common denominator for example 4/7 - 3/6 7 is a prime number so we will have to use 7 * 6 = 42 (4/7)(6/6) = 24/42 (3/6)(7/7) = 21/42 now what is 24 -21? three so 3/42 which is 1/14 Please stop guessing and try to do the problems.

Math
number 3 2/9 + 6/9 = 8/9 in my world

Math
Number 2 ? if you add 1/2 and 1/2 do you get 2/4 = 1/2 ?

Math
.... and luckily 6 inches is exactly half a foot :)

Math
I just used the equation you gave me (which is standard anyway) y = m x + b now I want to find out where that line hits the x axis the x axis is where y = 0 (draw an x y graph) so I set y to zero in your equation 0 = m x + b then I subtracted b from both sides then I divided ...

Math
The x axis intercept is the value of x when y = 0 0 = m x + b m x = -b x = -b/m

math
3 candles --> 5 years old 6 candles --> 10 years old 9 candles --> 15 years old etc

math
y = base + 100 s/1000 2300 = base + 100 (5000)/1000 2300 = base + 500 base = 1800 y = 1800 + 100(7500)/1000 y = 1800 + 750 y = 2550

mathematics
in general for AP the form is: Xn = a + d(n-1) Now look at 3n + 4 Xn = 4 + 3n let a = 4 let d = 3 Xm = 4 + 3 (m-1) where m = n+1 m = 1 to 5 4, 7 , 10 , 13 , 16 then 14 - 4 n again a = 14 d = -4 m = n+1 Xm = 14 - 4(m-1) etc

Science (Plz help)
Here are some links: http://www.kidspast.com/world-history/0007-ice-age-human-evolution.php http://ask.mrdonn.org/earlyhumans/14.html https://www2.palomar.edu/anthro/homo/homo_3.htm

Science (Plz help)
Ice age impact on humans

math
making table Angle, left side 0 ,,,,, 12 30 ,,,, 12.89 40 ,,,, 12.41 hmm 24 ,,,, 12.996 <---- around 24 degrees 25 ,,,, 12.99 26 ,,,, 12.97 27 ,,,, 12.96 28 ,,,, 12.94 29 ,,,, 12.91

Physics
component of weight down ramp = 1130 * 9.81 sin 25 component of cable tension up ramp = T cos 31 so T cos 31 = 1130 * 9.81 * sin 25 Part B weight component normal to ramp down 1130 * 9.81 * cos 25 reduce by component of T up normal to ramp T sin 31 so 1130 * 9.81 * cos 25 - T ...

Physics
w^2 R = 9.81 w^2 = 9.81/163 w = .245 radians/s rpm = .245 rad/s * 1 rev/2 pi rad * 60 s/m

algebra
x+1 + 2x-3 =

Science
I guess we have four wheel drive. The tires are pushing back on the road. (at least the tires that are driving the car forward) Newron's Third Law - reaction equal and opposite to action

math
I think maybe it is assumed a rectangular prism ? (x^2+2x)(x-1) = x^3 + x^2 - 2x

History
Well, those are the ones I question :)

History
C? What??? !!! Being a scientist I think B and C are absolutely nuts.

further maths
Xn = a r^(n-1) X5 = a r^4 X4 = a r^3 ar^4 -ar^3 = 13.5 X3=a r^2 ar^3-ar^2 = 9 ---> ar^4-ar^3 = 9r so 13.5 = 9 r I think you can take it from there.

Math
<CAB = 60 c = 8 b = 9 law of cosines a^2 = b^2+c^2 - 2 bc cos 60 a^2 = 81 + 64 - 72(1/2) a^2 = 109 a = 10.44 then use law of sines to find other two angles

pre-calc
p(x) = (x)* (x-a)(x-b) if x = 2, p = -4 p(2) = -4 = (2)(2-a)(2-b) -2 = 4 -2a - 2b + ab -6 = -2a -2b + ab p(4) = 0 0 = (4)(4-a)(4-b) -16 = - 4a -4b + ab 10 = 2a +2b 5 = a + b b = 5-a p(x) = (x)* (x-a)(x-b) p(x) = x * (x-a)(x+a-5) if x = 2 -4 = 2*(2-a)(-3+a) -2 = -6 +5a -a^2 a^2...

pre-calc
p = (x+3)(x+1)(x-2)(x-a) which is not cubic at x = 0, p = 6 6 = 3*1*-2(-a) 6 = 6 a a = 1 so p = (x+3)(x+1)(x-2)(x-1) multiply that out

Physics
force down on ground = 50*9.81+315sin 21 so friction force = .21(50*9.81+315sin 21) so in the horizontal direction F=ma= 50 a = 315cos21 -.21(50*9.81+315sin 21) solve for a I assume that the initial speed is zero then x = (1/2)a t^2 = 112.5 * a

Physics
m g = m(9.81) = 45 so m = 45/9.81 kg on earth

typo
ii) a = Fm NO a = F/m but you seem to have divided ok anyway a = 1.3?10^8N*7.5?10^12kg =1.73?10^?5ms^?2 What is this>? 1 7.5?10^12 ?(1.2?10^8N,5.0?10^7N) = (1.6?10^?5N,6.667?10^?6N)ms^?2

mathematics
Xn = a + d(n-1) 10= a + d(9) 0 = a + d(4) ------------- subtract 10 = 5 d d = 2 a = -8 so X20 = -8 + 2*19 = 30

physics
https://www.grc.nasa.gov/www/k-12/airplane/otto.html

Maths
As far as I know the only way to make the square root of 2 rational is to multiply or divide it by the square root of 2.

science
https://brilliant.org/wiki/energy-level-and-transition-of-electrons/

University of Liberia , Chemistry
.1 L * 15 = 1.5 L

University of Liberia , Chemistry
First How many mols? 1.25 Mols/Liter * 0.488 Liters = 0.610 Mol KCl = 39+35.5 = 74.5 grams/mol 0.610 * 74.5 = 45.4 grams

Here is another slightly different way[16^(3/2)]^-1/6 (4^3)^-1/6 4^-1/2 1/4^(1/2) 1/2 .5

Chemistry
I think it is indeed A and D but also is B and C. It it is an "it" it has a wavelength :)

(3 ^1/3)^6 / (5^1/2)^6 3^2/5^3 9/125

History
Seven trips China --> Indian Ocean, traded the whole way. (was it not you I suggested google the Strait of Malacca?) If the Chinese had followed up on his work, the world would be very different.

History
By the way, extreme efforts were made by the British, particularly Prime Minister Chamberlain, to compromise with Hitler in Europe. The result was invasion of Poland by Germany and all out war until the Axis was totally defeated. WW2 in both East and West was a time when ...

History
As has been pointed out, attempts were made at compromise BEFORE Pearl Harbor.

history
No! Japan had no choice about surrender. Even if atomic bombs were not dropped on Nagasaki and Hiroshima by the US their Naval forces were defeated in the Pacific and they faced running out of food and oil. Japan is a limited resource island chain and depends on trade for ...

algebra
c = m if n<50 c = m + a(n-50) if n>/= 50 11.22 = m + a (67-50) is 11.22 = m + 17 a 13.50 = m + a(n -50) you have to know n, the number of songs in September.

Simple harmonic motion
By the way 2760/2 pi is about 440 Hz to hear a 440 Hz test tone use: https://www.youtube.com/watch?v=Awx8-mq8g6g

Simple harmonic motion
x(t) = A sin(?t + ?) v(t) = A ? cos(?t + ?) a(t) = - A ?2 sin (?t + ?) = -?^2 x(t) so x(0) = A sin(?) v(0) = A ? cos( ?) a(0) = - A ?2 sin ( ?) = -?^2 x(0) at t = 0 x(0) = 160 sin(?) v(0) = 160*2760 cos( ?) a(0) = -2760^2 160 sin(?) if ? = pi/2 x(0) = A = 160 v(0) = A ? * 0 = ...

Chemsitry
molar mass of Al is 27 g/mol we used .506 g/27 g/mol = .0187 mols of Al for every mol of Al we get a mol of K[Al(OH)4] so .0187

history
In January of 1942 my mother and I flew from Pearl Harbor to San Francisco. People in California were much more scared than those of us on Oahu.

Math
I did it the physics way. Use Reiny's parabola if you have not had physics and calculus.

Math
H is the height, not t. You used t = 4 for H another way (dH/dt) = v velocity = v = -32t + k at top: v = 0 = -32 t + k k = 32 t = 32 * 4 = 128

math
2 is wrong 1/20 = .05 not .2 3 is right but should be written 2 3/5 because 6/10 = 3/5

tourism and hospitality
I suspect A is right but not my thing.

tourism and hospitality
http://www.howdesign.com/product-branding/

History
You are welcome.

History
Yes

Math
Perhaps angle D is angle GDE and angle F is angle GFE? If so you have two angles the same in the two triangles DEG = FEG (bisect of DEF) GDE = GFE given so DGE = FGE anlges in triangle add to 180, if two are the same so is the third EG is common to both triangles so triangle ...

The reason
No one is replying is that the way you have described this problem makes no sense. What are angles D and F ? if E to G bisects angle DEF then DEG is congruent to FEG

History
Glad you found one more :) Once again the alternate answers are really crazy.

Algebra
(b^.5 + 3^.5)*(b^.5 + 3^.5) ------------------------- (b^.5 - 3^.5)(b^.5 + 3^.5) is (b + 2(3b)^.5 + 3) ------------------- (b-3)

History
b is correct.

simple harmonic motion
v(t) = A? cos(?t + ?) this is zero when (?t + ?) = pi/2, pi/2+pi, etc so you can find t when v = 0 HOWEVER if you just want the maximum value of v it is A? because cos is between -1 and + 1 same with max of a is A?^2

Maths
they add up to 360 so 160

Algebra
25 -------- 3 sqrt(225z) well 225 = 25 * 9 so 25 ---------------- * sqrt z/sqrt z 3 * 5 * 3 sqrt z 5 sqrt z ------------------ 9 z

history
I was present at the time (first grade at Punahou school). I remember conflict but no compromise. The Japanese attacked our ships and airports from the air from aircraft carriers north of the island. Everyone who could got their ships and planes underway and people like my ...

History
Well, Pocahontas was from Virginia :) So yes But he also named lots of stuff around here on Cape Ann --- Tragabigzanda, Turks head islands

Chemistry
molar mass of F = 19 so F2 is 38 grams/mol so we have 361/38 mols of F2 we get half as many mols of N2F4 so 361/76 mols of N2F4 molar mass of N2F4 = 28 + 76 = 104 grams/mol so 104 * 361 / 76 grams

Physics
Ke of toy car =(1/2) m v^2 = m g h so v = sqrt(2gh) = sqrt(2*9.81*0.7) v = 3.71 m/s momentum = 0.05*v = 0.185 kg m/s so 0.2 u = 0.185 u = 0.926 m/s

math
Xn = a r^(n-1) X2 = a r = 2/3 X5 = a r^4 = 1/2 so X5/X2 = r^4/r = (1/2)/(2/3) r^3 = 3/4 r= .75^(1/3) a r = 2/3 a [.75^(1/3)] = 2/3 solve for a which is the first term ar^3 = a * (2/3) which is term 4

disagree with f.
vf = a t

Physics
weight = m g = 64*9.81 = 628 Newtons normal force = 628 cos 18 = 597 Newtons parallel force = 628 sin 18 = 194 Newtons mu * normal force = .04*597 = 24 Newtons total force down slope=194-24= 170 Newtons so a = F/m = 170/64 = 2.65 m/s^2 (check that is about .27 g which is a bit...

phyics
F = k Q q/R^2 E = F/Q = force per unit charge = k q/R^2 k = 9*10^9 N m^2/C^2 q = 4 * 10^-9 C R = 2

physics
force of gravity = G M m/R^2 if mass is m, what is escape speed from R, M (1/2) m V^2 speed V at R = work done falling from infinity to R (1/2) m V^2 = integral oo to R of F dr (1/2) m V^2 = (G M m/R^2) dr = (GM)(1/R) V^2 = 2 G M/R if R = 1/4 Radius earth and mass = (1/2) mass...

math
The one where x+y = 13

Math
https://www.jiskha.com/display.cgi?id=1508965486

Math
c + 3

History
Agree once again :) Once again whoever writes your questions has a sense of humor. It is not d :)

English
2 or 5 depending on if you hold the straw with its long axis vertical or horizontal. Normally it would be 5, blowing over the hole in the top of the straw.

not quite
my try: x^2 -12 x = -y - 4 x^2 - 12 x + 6^2 = -y -4 + 36 (x-6)^2 = -y + 32 so (y-32) = -(x-6)^2 vertex at (6 , 32)

Math
10 - 6 = 4 still

for example number 9: (2.2)(5.8) = (2.2)(z/2.2) so (2.2)(5.8) = z

rules
rules of the road for numbers 3 on You can add (or subtract) the same thing to both sides of an equal sign. You can multiply(or divide) everything on the left by the same thing you multiply (or divide) everything on the right

You try first
Clearly I already know how to do these. You are supposed to learn how. Please try to do them so I can figure out what you are missing.

tourism and hospitality
LOL, yes !

Math
(-5 * -2) - 6 10 - 6

Physics
so both gravity and friction are pushing down the slope? F = m g sin 25 + mu m g cos 25 a =F/m = g sin 25 + .5 g cos 25

Algebra
You are welcome.

Algebra
A: M = 16 x B: T = 16*30 + 20 y (y,not x, is overtime hours) C: 580 = 16*30 + 20 y 580 = 480 + 20 y y = 100/20 = 5 hours over 30 so 35 hours total

science
I guess you mean medicine maybe. A disease carrier is someone who carries the bug, transmitting it to others, usually without showing symptoms. Google typhoid Mary https://en.wikipedia.org/wiki/Mary_Mallon

physics
vertical problem: goes up 150 m (remarkable throw) v = Vi - g t v = 0 at top Vi = g t = initial up component of speed h = Vi t - (1/2) g t^2 150 = Vi t - (1/2) g t^2 150 = g t^2 -(1/2) g t^2 300 = g t^2 300/9.81 = t^2 t = 5.53 seconds upward, 11.1 total in air Vi = 9.81*5.53...

Physics
Linear m v = .141 *2.35 angular I omega = (1/2)*.141* 0.155^2* (55)

Science
Do you use a meter stick for those ?

Science
How long does it take is time !

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