Sunday
September 25, 2016

Posts by scott

Total # Posts: 1,255

chemistry
carbon dioxide is 32/44 oxygen by mass 3.70 g / (32 / 44)
September 24, 2016

physical science
weight is directly proportional to mass and gravitational acceleration ... w = m g w = 81.4 * (8.87 / 9.81)
September 24, 2016

Physics
f = m a m g - t = m a t = m g - m a = m (g - a) t = 2.45 (9.80 - 2.55) answer units are Newtons
September 24, 2016

physics
the free-fall equation is ... h = -4.9 t^2 + 12 t + Hb a. 0 = -4.9(3.4)^2 + 12(3.4) + Hb b. Tmax = -12 / (2 * -4.9) ... plug Tmax into the free-fall equation to find Hmax c. v = g(3.4 - Tmax)
September 23, 2016

PHY
h = 1.41 tan(34.7º)
September 22, 2016

physics
the increase in kinetic energy is from (equal to) the decrease in gravitational potential energy v^2 = 2 g h = 2 * 980 * 40 sin(.1 rd)
September 19, 2016

Physics
50 (5 + d) + 25 d = 200 (5 - d) 250 + 75 d = 1000 - 200 d 275 d = 750
September 19, 2016

PRE-CAL
2 = e^(11r) r = ln(2) / 11 1600 = P e^[10 ln(2) / 11]
September 17, 2016

Maths
a + b = 8 7 a^2 = 2 b^2 + 13 7 (8 - b)^2 = 2 b^2 + 13 448 - 112 b + 7 b^2 = 2 b^2 + 13 5 b^2 - 112 b + 435 = 0
September 17, 2016

Physics
from the general free fall equation 0 = -4.9 t^2 + 5 t + 98 v = -9.8 t + 5
September 17, 2016

Physics
see earlier post
September 16, 2016

Ashley
the distance equals the flight time multiplied by the horizontal component of the takeoff speed t = 2 {[s * sin(27.1º)] / g} d = t * [s * cos(27.1º)] 7.73 = 2 * s^2 * sin(27.1º / 2) / g
September 16, 2016

Statistics
see earlier submission
September 14, 2016

Math
p(not correct) = 1 - .797 p(at least one) = 1 - p(none) p(none) = (1 - .797)^3
September 14, 2016

Chem
g/ml * ml ---> g
September 14, 2016

Physics
one cycle (rotation) in 12 hrs (12 * 60 * 60) sec per cycle (1 / 43200) hz
September 14, 2016

chemistry
c - 44 = f f = (9/5 c) + 32 substituting ... c - 44 = (9/5 c) + 32
September 13, 2016

precalc
w^2 + (π/2) (w/2)^2 = 240 ft^2 w^2 [1 + (π/8)] = 240
September 13, 2016

chemistry
the ratio of NH3 to H2O is 4:6 or 2:3 NH3 / 2 = H2O / 3 NH3 = 2/3 * H2O 2/3 * 8 = ?
September 13, 2016

math
5 + 4i
September 13, 2016

RPS
6a + 5d = 6 ... a = 1 - 5d/6 (2a + d) (5a + 4d) = -80 ... 10 a^2 + 13 ad + 4 d^2 = -80 substitute for the value of a solve for d substitute back to find a
September 12, 2016

math
looks good
September 12, 2016

physics
looks like gravitational potential energy the energy equals the mass of an object, multiplied by the gravitational acceleration, multiplied by the height of the object
September 12, 2016

Physics
100 N * sin(45º) * 10 m = ? Joules
September 12, 2016

Physics
the height of the tree is ... 54 tan(30º) m
September 8, 2016

algebra 2
mary has a two hour head start she is 120 mi (2 * 60) ahead when tom starts tom catches up at 10 mph (70 - 60) it takes tom 12 hr (120 / 10) to catch up 12 hr from 8 am is 8 pm
September 6, 2016

physic
speed = wavelength * frequency so, the speeds are in the same ratio as the wavelengths sglass = sair (wglass / wair)
August 31, 2016

SCIENCE
you're multiplying 3 sf by 4 sf the result will have the smaller number of sig figs a trailing zero without a decimal point is not significant
August 31, 2016

Math
this is a Pythagorean triple ... 3-4-5 times 2 ... 6-8-10 x^2 + (x + 2)^2 = 10^2 2x^2 + 4x - 96 = 0 x^2 + 2x - 48 = 0 (x + 8) (x - 6) = 0 x = 6 ... x + 2 = 8
August 28, 2016

Chemistry
distributing on the right ... 3.6 v = 2.7 v + (2.7 * 4.9) subtracting 2.7 v ... .9 v = 2.7 * 4.9
August 27, 2016

Chemistry
How did the left side of the equation went from 3.6*V to .9V?
August 27, 2016

Chemistry
p₁ v₁ = p₂ v₂ 3.6 * v = 2.7 * (v + 4.9) .9 v = 2.7 * 4.9 ... v = 14.7 the evacuated flask means that no additional air was introduced into the system ... just a volume increase with a corresponding pressure decrease
August 27, 2016

Chemistry
A flask of known volume was filled with air to a pressure of 3.6atm. This flask was then attached to an evacuated flask of known volume and the air was allowed to expand into the flask. The final pressure of the air (in both flasks) was 2.7atm and the volume of the second ...
August 27, 2016

physics
a slingshot launches a rock straight upward at 25 m/s, how high does the rock go, how long is it in the air, what is the velocity and the acceleration of the rock at its highest point
August 27, 2016

physics
a greyhound is capable of running at 40 mph, how many meters could the greyhound run in 3 minutes at this speed, how many seconds would it take the greyhound to run 1 km at this speed
August 27, 2016

Chemistry
so the concentration of H⁺ from the HCl is ... 1 mole in 6 moles of water pH is based on moles of H⁺ per liter of solution water's volume is 18 mL per mole (based on the molar mass) so 6 moles is 108 mL so, [H⁺] = 1 mole / .108 L pH is the negative log of...
August 27, 2016

Physics I - Modern
the momentum is the product (multiply) of the relativistic mass and the velocity the relativistic mass is the rest mass multiplied by gamma (the relativistic "fudge factor") gamma = 1 / sqrt[1 - (v² / c²)] p = gamma * rest mass * v hyperphysics (web) is a ...
August 25, 2016

math
that is the number for all correct (or incorrect) see the answer to your other posted question
August 24, 2016

math
(a) it is a normal distribution (bell curve)n with the most likely score being half right (or wrong) you could plot the points using your binomial distribution from part (b) (b) the exponents in an individual term should sum to 15 only your last term does that otherwise, looks...
August 24, 2016

Chemistry
H₃BO₃ is triprotic (3 H⁺ per molecule) 29.15 * .025 = M * 3 * 25.0
August 23, 2016

Algebra
x (7 - 2x) (12 - 2x) = 33 4x³ - 38x² + 84x - 33 = 0 (9 - √15) / 2
August 23, 2016

Physical science check my answers
4. traveling a greater distance in the same amount of time means you went faster/slower?
August 23, 2016

Chemistry
a dm^3 is a liter two chloride ions per calcium chloride molecule .04 * .45 * 2
August 22, 2016

solid mensuration
π r² = 452 ... r = 12 the triangle formed by the chord and the radii from the ends has a central angle of 120º so 2/3 of the circle (240º / 360º), plus the area of the triangle; is the area of the larger segment
August 21, 2016

Physics
A. 239 = ½ * 3.7 * t² B. v = a t = -3.7 * t ... t is from part A
August 21, 2016

Physics
A. t = 50 ft/s / 32.2 ft/s² B. the velocity is zero at the peak ... so the average ascending velocity is 25 ft/s ... the displacement is 25 ft/s multiplied by the time from part A C. the time is half of the time from part A ... the average velocity is (50 + 25)/2 ft/s...
August 21, 2016

Algebra
you are correct (-11)^2 would be 121
August 21, 2016

Math
W = H + 4 L = W + 8 = H + 4 + 8 = H + 12 A = 2H (W + L) = 2 H (2H + 16) 512 = 4 H² + 32 H 128 = H² + 8 H 0 = H² + 8 H - 128 solve for H, then substitute back to find W and L
August 21, 2016

trigonometry
11π / 12 corresponds to a 15º reference angle in Q II 15º is half of 30º use a half-angle identity to find the exact value
August 20, 2016

Physics
the man is twice as far from the fulcrum as the rock so the effort is half the weight of the rock
August 20, 2016

PHYSICS topic is pressure
it is the lowered PARTIAL PRESSURE of oxygen, coupled with the increased PP of carbon dioxide that causes problems
August 20, 2016

PHYSICS topic is pressure
a deep well allows for little air circulation and the components of the atmosphere can stratify to a certain extent oxygen (which we need to breathe) is not the densest component the noble (inert) gas, argon, makes up about 1% of air; and is the heaviest as already mentioned, ...
August 20, 2016

SCIENCE
see the physics question 3 above yours
August 20, 2016

Maths Algebra
b = g + 334 b + g = 572 substituting ... g + 334 + g = 572
August 20, 2016

Trig
a sine value of .5 means a 30º reference angle in Q III, the angle is ... 180º + 30º = x
August 20, 2016

Maths Algebra
3/5 = 24/40 1/4 = 10/40 1/8 = 5/40 1/40 is left for foot travel 1/40 j = 2 km ... j = 80 km
August 19, 2016

Maths Algebra
9 is 1/4 of 1/2 of the herd 1/8 h = 9
August 19, 2016

Algebra
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August 17, 2016

Math
46 divided by 1
August 17, 2016

Physics
the kinetic energy of the ball at launch equals the gravitational potential energy at the peak ½ m v² = m g h v = √(2 g h) = √(2 * 9.8 * 20) m/s
August 17, 2016

Trigo
the length of belt that passes over the pulleys is the same 18 * 2π * 6 = 5 * 2π * r
August 17, 2016

Science
yes
August 17, 2016

Math
the force is proportional to the area 30 N / 50 cm² = f / 1500 cm²
August 16, 2016

mathematics
30000 = x [1 + (.12/12)]^(5 * 12) 32500 = y [1 + (.12/12)]^(7 * 12) 36000 = z [1 + (.12/12)]^(10 * 12) find x, y, and z and add them together log(3000) = log(x) + 60 log(1.01) log(3000) - [60 log(1.01)] = log(x) 10^[log(x)] = x
August 16, 2016

maths
12 is the common denominator for 6, 3, and 4 10/12 - 8/12 + 15/12 = 17/12 = 1 5/12
August 16, 2016

Math
3/5 men...so 2/5 women the difference (1/5) equals 12 5 * 12 = ?
August 16, 2016

Maths
torque = force * distance 200 Nm = f * .40 m
August 16, 2016

PreCalc
you want the sin⁻¹ function on your calculator sin⁻¹(0.65) = Θ = .7076 , 2.4340
August 15, 2016

Math
8+{4 x [(2+7) / 3]} = 20
August 15, 2016

PHYSICS/SCIENCE
a third as much as 15.0 g
August 13, 2016

Math
x² + 7x + 12 = 0 (x + 3) (x + 4) = 0 x = -3 , x = -4
August 13, 2016

Physics/Science
150 cal to take the water to 0º C 79.7 cal/g to freeze it
August 13, 2016

Math
c = 3.5 x + 10
August 12, 2016

Math-Direct Variation
x = k y 3 = k * 6 ... k = 1/2 x = 1/2 * 2/3 = 1/3
August 12, 2016

probability statistics
between means ... 4000 < n < 7000 3 choices for the 1st digit ... 4, 5, 6 8 for the 2nd digit 7 for the 3rd digit 6 for the 4th digit numbers = 3 * 8 * 7 * 6
August 12, 2016

statistics
there are 11 letters 3 of them occur twice possible arrangements equal ... 11! / (2! * 2! * 2!)
August 12, 2016

Calculus
velocity is dx/dt integrating gives position t/42 = dx/dt t/42 dt = dx integrating ... t²/84 = x = 100/21
August 10, 2016

math
there are 9C4 ways of selecting four printers there are 5C4 ways of selecting four good printers the probability is ... 5C4 / 9C4
August 10, 2016

Science
the simplified range equation is ... Rmax = v² / g ... 100 = v² / g ... 100 g = v² when an object is thrown straight up, the initial kinetic energy becomes gravitational potential energy ... ½ m v² = m g h ... v² / (2 g) = h combining the two ...
August 8, 2016

math
b + c = 45 / 2.5 = 18 kph b - c = 39 / 3.25 = 12 kph adding equations (to eliminate c) ... 2 b = 30 kph solve for b substitute back to find c
August 7, 2016

chemistry
a mole contains Avogadro's number of particles 5 moles = 5 * 6.02E23
August 7, 2016

Geometry
90º - a = (180º - a) / 5 450 - 5a = 180 - a 270 = 4a
August 7, 2016

Algebra/Quadratic Functions
the minimum lies on the axis of symmetry x min = -b / 2a = -(-200) / 2*2 = 50
August 7, 2016

Calc
f(x) = x^2+(1000-x)^2 ... = x² + 1E6 - 2000x + x² ... = 2x² - 2000x + 1E6 the minimum is on the axis of symmetry at x=500 ... the function increases from there so as x increases (below x=500), the function decreases f(0) = 0² + (1000 - 0)² = 1000²...
August 7, 2016

Math calculus
s.a. = 6 s² da/dt = 12 s ds/dt v = s³ ... 8 = 2³
August 7, 2016

Maths
M = 2R M + 11 + R + 11 + 3 = 75 Roy's dessert ... 11 + 3 = $14 3R + 25 = 75 ... R = 50/3 Roy's meal ... $50/3
August 7, 2016

Science
f = 1500 * g * .2
August 6, 2016

maths
4 (1 / 2 μf) = 1 / Ce Ce = 2 μf / 4
August 6, 2016

Math
d = h cot(32º) d - 8 = h cot(43º) 8 = h [cot(32º) - cot(43º)] h = 8 / [cot(32º) - cot(43º)]
August 6, 2016

Math
3/5 = 6/10 ... so there were 6 groups of boys the 2/5 of the class that were girls resulted in 2 groups of 1/5 each an aside ... the girls' groups were twice as large as the boys' groups
August 5, 2016

physics
don't know if significant figures are an issue but there are two in the data, and four in the result
August 5, 2016

Science
the horizontal velocity is the total velocity multiplied by cos(30º) at the topmost point, there is no vertical velocity ... so the K.E. is ... E cos²(30º)
August 4, 2016

Algebra
nancy starts with $50 more, but annie can save $5 more per week 50 / 5 = 10 weeks
August 4, 2016

physics
h = ½ g t² + 30 t = -4.9 t² + 30 t substitute 20 for h to find the time ... use the quadratic formula the time of max h is on the axis of symmetry of the parabola ... t = -b / 2a = -30 / -9.8 ... plug in the time to find h max the velocity is zero at max h the...
August 4, 2016

physics
average velocity = distance / time = 42 m / 2 s = 21 m/s average velocity = (initial + current) / 2 gravity slowed the arrow for 2 sec ... current = initial - (2 * 9.8) (Vi + Vi - 19.6) / 2 = 21 m/s solve for Vi time up = time down flight time = 2 (Vi / g)
August 4, 2016

Math
5 pies means 20 quarters (5*4) 3 quarters per neighbor means 6 neighbors, with two quarters left over 3*6 = 18 ... 18 + 2 = 20
August 4, 2016

I need help - precalc
1/√3 is the tangent of 30º or π/6 ... this is the reference angle -1/√3 is the tangent of the reference angle in quadrants II and IV so the x-values are ... 5π/6, 11π/6, and 17π/6
August 4, 2016

Math
no it is three decimal places to the right, so it is one thousandth the value of the 1st five (10^-3)
August 4, 2016

math
you could say "a" percent is like "a" peanut...one it doesn't use the term "percentage" regardless, the question is not well worded (1.01 n) * .20 = 400
August 4, 2016

biology
the high specific heat will help keep the pond from becoming a "fish stew"
August 4, 2016

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