Posts by Scott

Total # Posts: 2,557

algebra
(4y + 1i)(4y - 1i)

Physics
if his last turn is to the south he will be 70 m S and 12 m W of his starting position use Pythagoras to find the displacement

GENERAL PHYSICS
100 * 2π / 60 / 2 sec

math
36 / 47 = x / 120

Chemistry
mole = 6.02E23 particles 5.43E24 / 6.02E23

math help
1/2 * b * h = 10 b = h + 1 substituting ... h^2 + h - 20 = 0 (h + 5)(h - 4) = 0 h - 4 = 0

Physics
A) 2 * 7 * 10 N to the left B) 2 * 1/2 * 10 * 7^2 J C) the PE from B is converted to KE ... v = √[2 * B / m]

math
a = 2 pt, b = 4 pt, c = 5 pt a + b + c = 28 2a + 4b + 5c = 100 a = 2c 2a + 2b + 2c = 56 ... substituting ... 3a + 2b = 56 4a + 8b + 10c = 200 ... substituting ... 9a + 8b = 200 subtract the equations (after multiplying) to eliminate b

Physics
a faster stop (because concrete is hard) means a greater impulse

physics
the ball's speed is being converted to gravitational potential energy 1/2 m 6.4^2 = ... m g (2.2 - 1.5) + 1/2 m v^2 6.4^2 = 1.4 g + v^2

Math
s + b + w = 42 s = 4b 3s + 2b + 1.5w = 102 substituting ... 5b + w = 42 ... 14b + 1.5w = 102

Math
2 ft^3 = 2 * 12 * 12 * 12 in^3 24 * 144 / 231

phy 101
momentum is conserved so they "trade" velocities

Math
64, 32, 16, 8, 4, 2, 1, 1/2

Physics
a. weight = mass * g b. normal force equals weight ... but in opposite direction c. Newton's 2nd law ... f = m a ... in this case ... a = f / m d. correct

Chemistry
molar mass of acetone ... 58.08 g moles of acetone ... 1.920 / 58.08 molar enthalpy is energy per mole

Physical science
(A) m g h = 15 m g (B) m g h = 1/2 m v^2 ... v = √(2 g h) = √(30 g)

Math
it takes 12 min (the LCM of the numbers) divide by their rates to find the number of laps

Math 1105
yes

Physics
there is no force in the horizontal direction (gravity is vertical), so the horizontal velocity remains constant

math
the longest side must be less than the sum of the two shorter side the difference between the longest and shortest sides must be less than the middle side L + A = 11 L < (A + 4) ... L < (11 - L + 4) ... 2 L < 15 ... L < 7.5 L = 7, A = 4

Physics
A) 18 m/s * 6 s B) 1/2 g t^2

Math
1:12::8:x

chem
(a) 0.5 * (20.00 / 25.0) * (250.0 / 25.0) (b) multiply the answer from (a) by the molar mass of HCl

algebra
a + b = 273 / 3 mph = 91 mph a - b = 7 mph adding equations (eliminating b) ... 2 a = 98 mph

Physics
the horizontal velocity is ... 31 m/s * cos(60º) the vertical velocity is ... 31 m/s * sin(60º) + ... 3.4 s * -9.8 m/s^2 add the two component vectors ... a^2 + b^2 = c^2

problem solving
s = m - 8 m - 6 = 3(s - 6) = 3 s - 18 m - 8 = 3 s - 20 susbstituting ... s = 3 s - 20 ... 20 = 2 s

Physics
height = 1/2 g t^2 + Vo t + Ho 0 = -4.90 * .750^2 + Vo * .750 + 4.80

Physics
the difference in total energy (kinetic plus potential) at the base and the top; is the energy input from the engine the ascent time is the average speed, (top + bottom) / 2; divided by the 4.40 km distance energy / time equals power your answer has 5 sig figs. but all the ...

Physics
energy = m g h = 73.0 * 9.81 * 420 time = 60 * 15 + 10 power = energy / time

physics
his weight plus the centripetal force must equal 1170 N 83.0 [g + (v^2 / r)] = 1170 v^2 / 18.0 = (1170 / 83.0) - 9.81

physics
pulling at an angle reduces the frictional force (by reducing the normal force) so the frictional force is ... .42 * {(85 * g) - [F sin(38º)]} the block is in equilibrium when the frictional force equals the horizontal component of the pulling force ... F cos(38º) ...

Math
(n / 3) - 7 = 0 n / 3 = 7 n = 7 * 3

College Algebra
y = a b^x 8 = a b^0 ... a = 8 2.4 = 8 b^1 ... .3 = b y = 8 * .3^x

MATH
division by zero is a no-no ... even 0/0 so the 2nd and 4th are undefined

Algebra
Q = 5 * 2^(S + 4)

College Algebra
5 * 1.083^13

physics again
the water velocity increase is due to the change in gravitational potential energy 1/2 m 3.00^2 - 1/2 m 2.07^2 = m g h 3.00^2 - 2.07^2 = 2 g h the kinetic energy of the jump is converted to gravitational potential energy 6.26^2 = 2 g h the max waterfall is the sum of the two ...

physics
the average speed over the interval is (3.00 m/s + 5.60 m/s) / 2 = 4.30 m/s 2/3 of its length is 1.00 m so the time of the interval is ... 1.00 m / 4.30 m/s the change in speed is ... 5.30 m/s - 3.00 m/s acceleration is ... speed change / time

Physics
dx = (14 t - 32) dt x = 7 t^2 - 32 t + c 25 = 7 (3^2) - 32 (3) + c 25 = 63 - 96 + c ... 58 = c x = 7 t^2 - 32 t + 58

physics
gravity is the centripetal force keeping the satellite in orbit g = m a = 76 kg * .63 m/s^2

physics (super hard)
the centripetal force at the top of the circle equals gravity v^2 / r = g v = √(g r)

math
a. v = 1/3 * pi * r^2 * h b. the base radius is 4 and the height is 3, so the slant height is 5 (3-4-5 triangle) the 5 is the radius of the circle of which the area of the cone is a segment ... the area of the circle is...25 pi the area of the cone is...4/5 * 25 pi

math
7 is the most likely outcome using distinguishable dice, there are 36 possible outcomes ... each of the six faces on a die can pair with the six faces on the other die ... 6 * 6 = 36 twelve of those outcomes result in a sum of 7 ... one third of the rolls

Physics
k = f / e k1 e1 = k2 e2 e2 / e1 = k1 / k2

chemistry
call the 2nd gas B 3 g of B is half as many moles as 2 g of A B / A = 3 / 1

Jar Marbles
a) one of the five red marbles has the number 3 on it, so the probability is 1/5 b) two marbles have the number 1 on them, one red and one blue ... so the probability is 1/2

Maths
u = 2t - 6 10u + t = 10t + u + 9 substituting ... 20t - 60 + t = 10t + 2t - 6 + 9 solve for t, then substitute back to find u

physics
gravitational force follows an inverse-square relationship inverse of 1/8 is 8 ... 8 squared is 64

math
The Holy Father sent a courier from Rome to Venice, commanding him that he should reach Venice in 7 days. The most illustrious Signoria of Venice also sent another courier to Rome, who should reach Rome in 9 days. And from Rome to Venice is 250 miles. It happened that by the ...

Physics
the average velocity during braking ... (13.1 + 0) / 2 divide the stopping distance by the average velocity to find the time

Math
take out a common factor

Algebra
common factor 5x (x + 2)

Chemistry
the reaction equation is written in MOLES 2 moles NO plus 1 mole O2 yields ... 2 moles NO2 so 5 moles of O2 uses 10 moles of NO find the molar (formula) weight of NO, and multiply by 10

Physics
the delay time is down and back ... twice the depth

Physics
yes

Physics
how about 4 by 2.9 ...

Physics
time = √(2 * distance / acceleration) initial velocity = 2 (distance / time)

Chemistry
there are about 55.3 moles of water in a liter the mean (average) concentration of chloride ions will be twice the arithmetic average of the MgCl2 concentrations (two Cl- for each MgCl2) I would be tempted to disregard the 175 value as a "flier"...but that's up ...

Science Check my work PLS
#8 ... a range of 5 in the 3rd digit is fairly precise the accuracy is substantially flawed

Science
a = f / m = 3 / 1

physics
the period is related to the mass and the spring constant the amplitude is inconsequential

physics
momentum is conserved the 2nd (larger) piece moves in the opposite direction at 1/3 the speed

physics
P = m g h / t = 100 * 10 * 6 / 120 answer is in Watts

Calculus II
If f(x) - x cos (x), how many intervals would be needed to approximate with the Trapezoidal Rule with an error of E<.01?

Math 115
a million is a thousand thousand (276.5 / 3150.4) thousand per mi^2

Physics
Tn = d / 40 Ts = d / 60 Save = 2d / (5d / 120)

Physics
.6 g = v^2 / r

Calculus
f(x) = x^2 has a critical point (and a MINIMUM) at x=0 f(x) = (x^3 + 3x^2 - 4x - 12) / (x+2) ... has a critical point (and a "hole" at x=-2)

College math
p(white) = 9/24 = 3/8 p(green) = 8/24 = 1/3 p(w then g) = 3/8 * 1/3

Math (Condensing logarithmic expression)
ln{5^2 * [x / (x^2 + 1)^2]^3}

ACT math
h + s = 10 ... s = 10 - h 12 h + 14 s = 128 substituting ... 12 h + 14(10 - h) = 128 ... 12 h + 140 - 14 h = 128 ... -2 h = -12

Physics
gravitational potential energy becomes kinetic energy m g h = 1/2 m v^2 v = √(2 g h) = √(2 * 9.81 * 15.0)

Chemistry
the sulfite ion has a -2 charge Pb(SO₃)₂ the hydrogen phosphate compound is missing a subscript 4 Pb(H₂PO₄)₄

algebra 2
3/5 (∛5)^2

Physics
compressing 0 cm to 6 cm is equivalent to compressing 0 cm to 3 cm, and continuing to compress 3 cm to 6 cm although the compression lengths are the same for the two parts, the 2nd part takes more work because the resistance of the spring increases with compression 0 to 6 uses...

Calculus
points with the same x or y coordinate represent vertical or horizontal chords of the circle the perpendicular bisectors of the chords are diameters, and they give one of the coordinates of the center you can use the distance formula to find the other coordinate of the center ...

math
you don't show any of the data, but it's very likely that the line doesn't go through the origin (0,0) there is probably some base rental charge (represented by the intercept)

Chemistry
E = m g h ... h = E / (m g) h = 628 kJ / (70 kg * 9.81 m/s^2) 1 Joule = 1 kg m/s^2

Physics
the ball is uniformly accelerated by gravity average velocity = ... (final vel. + initial vel.) / 2 6.5 m / 3.1 s = (V fin + 0) / 2

Math (calculus 3)
the given height equation is incorrect ... the t^2 coefficient is -16, not -8 solve away...

MATH
try again when the bases are the same, just add the exponents 3^2 x 3^2 = 9 x 9 = 81 = 3^4 ... not 9^4

MATH
try again when the bases are the same, just add the exponents

help plzz asap
the trains are closing at 110 mph ... (50 + 60) t = d / r = 330 mi / 110 mph

Physics
the .410 coefficient means that the max acceleration is .410 g

v^2 / r = 5 g r = v^2 / (5 g) r = (288 km/h)^2 / 49 m/s^2 r = (80 m/s)^2 / 49 m/s^2

Math
Oops forgot one step Ignore my first answer Step 1.)5*15=x Step 2.)x*5=Answer

Math

Math~ Algebra 1
Thank You

Math~ Algebra 1
Two cars are traveling on the same highway. The first car is traveling at an average rate of 44mi/h. The second car leaves an hour late traveling at an average rate of 55mi/h. How long will the cars have traveled when the second car catches up with the first car?

Math
2 dived by 1/4= 8 banners

Science
the -256 C gas is hydrogen oxygen is -183 C they are both diatomic gases the volume of hydrogen (g) produced is twice the volume of oxygen (g)

Algabra
H < D < T H + 2 = D ... D + 2 = T 3 D = 2 T + 13 3 D = 2 (D + 2) + 13 = 2 D + 17

Math
draw a picture of the map for b they give you all the dimensions you need

Math
6 inches on the map equals 72 miles on the ground a. 1 inch equals 12 miles b. 2 inches on the map equals 24 miles on the ground

Math
L + P + N = 4050 L = P - 326 2 (L + P) = N L + P + 2L + 2P = 4050 L + P = 1350 (P - 326) + P = 1350 2 P = 1676

physics
the trains are closing at 50 kph (25 + 25) they start 150 km apart, so it takes them 3 hr to meet (and pass) the bird flies for 3 hr at 50 kph, so it flies 150 km

physics
the speed of sound in air is approximately 340 m/s the speed of light (from the flash) is approximately 3E8 m/s ... instantaneous for practical purposes so the distance to the bolt is ... 3 s * 340 m/s

Biology
if the dress absorbed red light, then red would not be reflected to your eyes ... the dress would not look red

chemistry
carbon dioxide is 32/44 oxygen by mass 3.70 g / (32 / 44)