Friday

July 31, 2015

July 31, 2015

Total # Posts: 2,129

**Physics or Math**

The torque is about the point (-1.3, 2.4), so treat this as your origin,. . . This makes the r vector (4.3, -2.4, 0)
*November 9, 2012*

**Physics**

Use conservation of momentum: (65+0.18)*2.47 = .18*24.3 + 65*vf where vf is final speed of the ice skater b).Again, use conservation of momentum: 0.18*24.3 = (62+0.18)*vf
*November 9, 2012*

**Physics**

sum(F) = m*a where sum(F) is the sum of the forces, m is mass, and a is acceleration: 30 - 20 = 50*a
*November 9, 2012*

**Physics**

400 = 2*a(cb) where a(cb) is acceleration of the cannon ball 400 = 500*a(c) where a(c) is acceleration of the cannon
*November 9, 2012*

**Physics**

F = m*a where F = force, m is mass, and a is acceleration 25 = m * 5
*November 9, 2012*

**college algebra, Please help!!**

A. is f(-2) = 9? if it is, then the point (-2,9) is on the graph. Otherwise, it's not on the graph B.Plug 2 into f(x) f(2) = 2 * (2^2) - 2 - 1 The points on this graph are (2, f(2)) C. Solve -1 = 2*x^2-x-1 You should find two solutions for x. D. The domain of f is the ...
*November 9, 2012*

**Physics**

For an elastic collision, both momentum and kinetic energy are conserved. m1 = mass of colliding ball m2 = mass of ball initially at rest v1i = initial speed of colliding ball v1f = final speed of colliding ball v2i = initial speed of at rest ball = 0 v2f = final speed of at ...
*November 9, 2012*

**math**

I say c 127.1 / (127.1+32.1) = %Cu 32.1 / (127.1 += 32.1) = %S
*November 9, 2012*

**physical science**

F*d = W Where F is force, d is distance moved, and W is work
*November 8, 2012*

**math**

$3.96 = 396 cents 396 cents / 17 ounces is price in cents/ounces
*November 8, 2012*

**math**

8:9
*November 8, 2012*

**Science**

Look up the speed of sound, then multiply this number by 6 s.
*November 8, 2012*

**Physical Science**

v = f*lambda where v is the speed of sound, f is the frequency, and lambda is the wavelength
*November 8, 2012*

**physics**

For an elastic collision, both momentum and kinetic energy are conserved. Conservation of momentum: m1*v1 + m2*v2 = m1*v1f + m2*v2f where m1 and m2 are the mass of the car and truck, v1 and v2 are the initial speeds of mass 1 and mass 2, and v1f and v2f are the final speed of ...
*November 8, 2012*

**math**

There are a total of 6*6 =36 possible combinations for a sum of 8, you can have: (6,2) (2,6) (3,5) (5,3) (4,4) Probability = 5/36 For a sum of 9, you can have: (6,3) (3,6) (4,5) (5,4) Probability of 4/36 For a sum of 10, you can have: (5,5) (6,4) (4,6) For a probability of 3/36
*November 8, 2012*

**PHYSICS**

The buoyant force acting on the balloon is (p1V1 - p2V2)g where V1 = V2 = 318 m3 p1 is the density of air p2 is the density of helium c) The net force is the buoyant force - m*g, where m is the mass of the balloon. If the net force is positive, the balloon will rise d BF - m*g...
*November 8, 2012*

**Math **

What value of b makes the equation below true? b+1/4=12/12 Please show work Thanks
*November 7, 2012*

**Math **

What value of b makes the equation below true? b+1/4=12/12 Please show work Thanks
*November 7, 2012*

**math HELP!!!!!!!!!**

Just multiply each coordinate by two (–1, 2) and (3, –3) gives ( -2 . . . . )
*November 7, 2012*

**Chemistry**

P1*V1 = P2*V2 when the temperature remains constant. P1 is the initial pressure, V1 is the initial volume, P2 is the final pressure, and V2 is the final volume.
*November 7, 2012*

**physics**

Centripetal acceleration is given by a = v^2/r = omega^2*r where a is the centripetal acceleration, v is the speed, r is the radius, and omega is the angular speed in rad/s Convert rev/s to radians per second 595 rev/s * (2*pi radians/rev) = ____ = omega a = omega^2 * 0.02 m b...
*November 7, 2012*

**physics**

-k*x = -Ke*q1*q2/r^2 where k is the spring constant, x is the distance stretched by the spring, Ke is Coulomb's constant, r is the distance between the charges. r = 9.00 cm = 0.09 m x= 5 mm = 0.005 m q1 = 2.70 uC = 2.7 * 10^-6 C q2 = -8.6 uC = -8.6 * 10^-6 C Ke = 8.9 * 10^9
*November 7, 2012*

**physics**

T = 1/f where f is frequency = 1.5, T is period
*November 7, 2012*

**algebra**

v - c = 1.5 v + c = 3.5 where v is Camille's speed in still water, c is the speed of the current Solve for v
*November 7, 2012*

**math**

dp/dx = 0, or -20x + 1700 = 0 Solve this for x for part 1, then plug this value of x into p(x) for the answer to part 2
*November 7, 2012*

**Math**

Write 2 24/12 as a whole number. Show work.
*November 5, 2012*

**Math**

At whole foods market 5/6 of the vendors sell vegetable and 2/4 sell fruit. What fraction of the vendor sell fruit or vegetable?
*November 5, 2012*

**Math**

Brenda mixed together 11/12 quart of cranberry juice and 8/15 quart of ginger ale to make punch. How much punch did Brenda make?
*November 5, 2012*

**Math **

C+1/5=9/20
*November 5, 2012*

**Math**

A capybara is the worlds largest rodent . It can grow to be 1 3/10 m long. Write an improper fraction that represents the length of the capybara? Please show work of how you got answer. Thanks
*November 5, 2012*

**Math**

An average 10 yr boy weighs 86 1/2 pounds and has muscles that weigh 34 1/5 pounds. An average 10 yr old girl weigh 82 1/3 pounds and has muscles that weigh 31 1/4 pounds. How much do an average 10 yr old boy and girl weigh together ? With answer can you tell me how you got it...
*November 5, 2012*

**Numerical Analysis**

xcosx-2x2+3x-1=0 Evaluate the function at 0.2 and 0.3: 0.2*cos0.2-2*0.2^2+3*0.2-1 = -.280 0.3*cos0.3-2*0.3^2+3*0.3-1 = 0.019 In order for the function to go from y=-.280 to y=0.019 on the interval [0.2,0.3], it must pass through y = 0 at least once. -x*sinx -4x + 3 =0
*November 2, 2012*

**Numerical Analysis**

The Taylor series about f(1) to fourth order is: f(x) = f(1) + f'(1)*(x-1) + f''(1)*(x-a)^2/2! + f'''(1)*(x-a)^3/3! The derivative of ln(x) is 1/x f''(x) = -1/x^2 f'''(x) = 2/x^3 f(1) = 0 f'(1) = 1 f''(1) = -1 f''...
*November 2, 2012*

**Numerical Analysis**

6 because there are 6 digits in 2.71828
*November 2, 2012*

**Numerical Analysis**

The Taylor expansion abour x = pi/4 to sixth order is f(x) = f(pi/4) + f'(pi/4)*(x-pi/4) + f''(pi/4)*(x-pi/4)^2/2! + f'''(pi/4)*(x-pi/4)^3/3! + f''''(pi/4)*(x-pi/4)^4/4! + f'''''(pi/4)*(x-pi/4)^5/5! f(x) = cos(x) f&#...
*November 2, 2012*

**Physics**

m*v^2/r <= cf*N where m is the mass of the object, v is the speed of the object, r is the radius, cf is the coefficient of static friction, and N is the normal force = m*g Solve for v
*November 1, 2012*

**science**

250 milliliters = 0.25 L; To make a 3.0 M NaOH solution from 6.0 M NaOH, you need equal parts of water and NaOH solution You need 0.25 Liters of the solution, so you need 1/2 * 0.25 = 125 milliliters 6.0 M NaOH, and 125 milliliters water
*November 1, 2012*

**Physics**

(1/p) + (1/q) = 1/f M = h'/h = -q/p, Where p is distance of object from lens, q is distance of image from lens, f is focal length of the lens, and M is the magnification f is positive when the lens is convex: 1/50 + 1/q = 1/15 q = 21.4 cm M = -21.4/50
*November 1, 2012*

**Physics**

F*r = I * a Where F is the force on the merry-go-round, r is the radius, I is the moment of inertia of the merry-go-round, and a is the angular acceleration for a solid, horizontal disk, the moment of inertia is: 1/2*m*r^2 F*r = 1/2*m*r^2*a F = 1/2*m*r*a w = w0 + a*t where w ...
*November 1, 2012*

**math**

Type 2 + (3/4) into your calculator
*November 1, 2012*

**physics**

The time elapsed between 12:35 and 3:10 is 2 hr, 35 min or 2 and 35/60 hours distance = 45 * (2 and 35/60)
*October 31, 2012*

**Physics**

dsin12.23 = ml, m = 0, 1, 2, â€¦.` where l = 550 * 10^-9 m d = 1/55000 solve for m
*October 31, 2012*

**algebra**

2(2-x)<-3x-2 Just start working with the equation as if the < sign was an = sign 4 - 2x < -3x -2 4 + x < -2 x < -6
*October 31, 2012*

**alegbra 1**

1). 3y=11-2x 2). 3x=y-11 Using equation 1: y = (11-2x)/3 Substituting into equation 2 3x = (11-2x)/3 - 11 x = (11 -2x)/9 - 11/3 x + 2x/9 = 11/9 - 11/3 11x/9 = 11/9 - 11/3 solve for x Then plug x into either equation 1 or 2, and solve for y 2) Use a similar procedure, as shown ...
*October 31, 2012*

**Math**

multiply everything out, then add like terms (2a+3b)(2a-3b) = 2a^2 +6ba -6ab - 9b^2 = 2a^2 - 9b^2
*October 30, 2012*

**6th grade Math**

In Euclidean plane geometry, a rectangle is any quadrilateral with four right angles. So a square is a rectangle. You could build up to a prime number of rectangles with a prim number of square tiles.
*October 30, 2012*

**math**

42/28 = 6/x Solve for x
*October 30, 2012*

**science**

I would think D). Snow can only form if the temperature is below freezing. Otherwise, rain falls.
*October 30, 2012*

**Physics**

The rotational kinetic energy of one wheel is 1/2 * I * w^2 where I is the moment of inertia of the wheel, w is the angular speed of the wheel. The total kinetic energy of the system is the sum of the rotational kinetic energies of each wheel, plus the translational kinetic ...
*October 30, 2012*

**Physics**

Mass never changes. It is always 95.7 kg Weight = mass * g, where g is the acceleration of gravity at that point
*October 30, 2012*

**physic**

24000 = 4000*a
*October 30, 2012*

**Physics**

There is not enough information here. You need to be given or have enough information to find rAB, rBC, rAC, where rAB is the distance between mass A and mass B, etc. The magnitude of the force acting on mass A is -G*mA*mB/rAB^2 - G*mA*mC/rAC^2 apply this same model to find ...
*October 30, 2012*

**math**

8*b = 64 where b is the number of boxes
*October 30, 2012*

**math**

$6*m = $24 where m is the number of mugs
*October 30, 2012*

**math**

8*d=56 where d is the number of days
*October 30, 2012*

**physics**

x = x0 + v0*t - 1/2*a*t^2 v = v0 - a*t m*a = m*g*uk where x is distance, x0 is the inital x position, v is speed, v0 is the initial speed, a is the acceleration of the crate, t is time, m is the mass of the crate, g is the acceleration due to gravity, and uk is the coefficient...
*October 29, 2012*

**science**

Please it's very important :)
*October 29, 2012*

**science**

What is a good way to study science? To be more specific Bellwork quizzes?
*October 29, 2012*

**Math**

The answer is c. A secant line is a line passing through 2 points of a function; since the tangent line only goes through one point, the slope of the tangent line to a function can't properly be defined as the slope of the secant at that point, because you haven't ...
*October 28, 2012*

**Physics**

w = 2*pi*f f = 1/19.9 where f is the frequency of the car going around the track, w is the angular speed around the track, pi is 3.14 w = 2*pi/19.9 =0.315 The speed traveled by one tire is w*r where r is the radius of the wheel The speed traveled by the other tire is w*(r+1.63...
*October 28, 2012*

**chemistry**

PV = nRT where P = pressure, V = volume, R is a constant = 8.314 J/mol*K, and T is temperature in degrees Kelvin, n is number of moles degrees K = 273 + degrees C 1 liter = 1000 cm^3 = 1000 cm^3* (1 m / 100 cm)^3 = 1000 * (1/1000000) = 1/1000 = 0.001 m^3 35 L = 0.0035 m^3 P*0....
*October 27, 2012*

**Math**

Change 30/20 into a mixed number
*October 25, 2012*

**Math**

8/12=
*October 25, 2012*

**Math**

How much larger is the 8 in 657,689,004 than the 8 in 789,456,234?
*October 25, 2012*

**english**

Direct characterization The author literally tells the audience what a character is like. This may be done via the narrator, another character or by the character him- or herself. Indirect characterization The audience must infer for themselves what the character is like ...
*October 25, 2012*

**math**

e^(ln(5-2x)) = e^3 5-2x = e^3 5-e^3=2x x = (5-e^3)/2
*October 25, 2012*

**physics**

The lift force L has an x and y component Lx and Ly: Lx = Lsin21 Ly = Lcos21 In the y direction, Lcos21 - 55600 = 0 Solve for L In the x direction Lsin21 - Fair = 0 where F air is the force of air resistance
*October 25, 2012*

**Physics!**

The first rope has an x component of force Fx1 and a y component of force Fy1: Fx1 = 57*sin 30 = 28.5 Fy1 = 57*cos 30 = 49.3 The second rope has an x component of force Fx2 and a y component of force Fy2: Fx2 = 57*sin 60 = 49.3 Fy2 = 57*cos 60 = 28.5 The net force in the x ...
*October 25, 2012*

**Math**

Ned caught 1/3 pound of fish. Sarah caught 5/12 pound of fish . Jessica caught 1/6 pound of fish. How much fish did all three of them catch?
*October 24, 2012*

**Math**

How much larger is the 6 in 657,879,004 than the 6 in 789,456,234?
*October 24, 2012*

**Math**

There are 10 tennis balls, 2 soccer balls, and 8 basketballs. What fraction in simplest form are tennis balls?
*October 24, 2012*

**Geometry**

Use the corresponding angles converse: If two lines are cut by a transversal and the corresponding angles are congruent, the lines are parallel. The transversal line is along the side of the ship parallel to the water, and the angles of the oars with the water are all ...
*October 24, 2012*

**Physics**

When it has stretched from its maximum position, the potential energy stored in the spring is 1/2*k*x^2 = 1/2*450*.5^2 = 56.25 this is converted to kinetic energy: 56.25 = 1/2*m*v^2 = 1/2*8*v^2 Solve for v
*October 24, 2012*

**math**

The twelve 1" cubes divided by /3 layers give 4 cubes/layer The shape is four layers of squares, 4 cubes on a side, or a cube with dimensions 4*4*4 cubes.
*October 24, 2012*

**Algrbra**

if 0≤x≤ 10000 : R(x) = $12 * 11% *x at x = 10000, R(x) = $12 * 11% *10000 = 13200 10000 < x ≤ 15000 : R(x) = 13200 + $12*12.5%*(x-10000) (The profit made on the first 10000 books + the profit made on books sold above 10000) at x = 15000, R(15000) = 13200...
*October 24, 2012*

**math 7 grade**

1*ch1 + 9*ch2 + 81*ch3 = 200 with ch1+ch2+ch3 <= 8 where ch1 is the number of charities belonging to the first group, ch2 is the number of charities belonging to the second group, and ch3 is the number of charities belonging to the 3rd group the number in charity 3 can only...
*October 24, 2012*

**Finance**

5000 * (1+x)^7 = 38700 Solve for x
*October 24, 2012*

**algebra 1**

Enter these data points into some graphing software, and ask the computer to perform a linear regression on the data (find the best-fit line that goes through the data points) The computer should also be able to calculate the correlation coefficient. If the correlation ...
*October 24, 2012*

**physics**

450 = m*v^2 / r where m is mass, v is speed, and r is radius
*October 24, 2012*

**pre-cal**

The initial velocity is in the y-direction. A) It's height above ground is y = x0 + v0*t - 1/2*g*t^2 where y is its height, x0 is its initial position, v0 is it's initial speed in the y direction, g is the acceleration due to gravity and t is time. Plugging in the ...
*October 24, 2012*

**physics**

the centripetal acceleration is omega^2*r where omega is the angular velocity, and r is the radius at that point 118 m/s^2 = omega^2*0.382 solve for omega, then find a : a = omega^2 * 0.0791
*October 24, 2012*

**physics**

1 hr = 60 min * 60 sec/min = 3600 s 73.2 s = 73.2 s / (3600 s/h) = 0.0233 hr 4mi / 0.0233 hr = 196.7 mi/h
*October 23, 2012*

**math**

There are 6 combinations for the first dice, and 6 combinations for the second dice, so the total number of possibilities is 36 There are only 4 ways to get a sum of 9: (4,5), (5,4), (3, 6), (6, 3) There are only 3 ways to get 4: (2, 2), (1,3), (3,1) There are only 5 ways to ...
*October 23, 2012*

**Physics**

For two lenses: 1/f = 1/f1 + 1/f2 where f is the focal length of the lens combination, f1 is the focal length of the first lens, and f2 is the focal length of the 2nd lens Extending this to 4 lenses: 1/f = 1/f1 + 1/f2 + 1/f3 + 1/f4 or 1/f = 1/200 - 1/125 -1/400 + 1/142.9 1/f...
*October 23, 2012*

**Calc**

a) First: the definition of a tangent line is defined as a line passing through a given point of a function whose slope is equal to the derivative of the function at that point The equation of the tangent line is of the form y = mx + b, where m is the slope, and b is the y-...
*October 23, 2012*

**Science**

The metric unit of distance is meters; The metric unit of time is seconds; The metric unit of speed is meters/second The units of distance and time are unrelated; the units of speed are defined in terms of metrical units of distance and time, or the rate of change of distance ...
*October 23, 2012*

**Physics**

w = w0 + a*t theta = w0*t + 1/2*a*t^2 where w is the angular speed, w0 is the initial angular speed, and a is the angular acceleration, and theta is the angle turned in radians, so 3.14*10^4 = 1.2*10^4 + a *t 1.92*10^4 = 1.2*10^4*t + .5*a*t^2 Solve this system of equations ...
*October 23, 2012*

**Physics**

Is this a trick question? The problem states that the mass of Puck A is 0.025 kg, and the mass of puck B is 0.060 kg. The collision does not change the masses, only the velocities
*October 23, 2012*

**Physical Science**

I don't think so, because if you can find a derivation for the buoyant force you will see that it depends on the fact that the pressure of a liquid increases with depth.
*October 23, 2012*

**Physics**

m*a = Liftforce - m*g In this case m is the combined mass of the helicopter and frame, so 9000*0.9 = Liftforce - 9000*g Solve for lift force B) Drawing a free body diagram on the frame: T - mg = m*a T - 1100*9.8 = 1100*0.9 Solve for T C) Drawing a free body diagram on the ...
*October 23, 2012*

**CHEMISTRY**

the heat capacities are given in units of moles and Kelvins, so you'll have to convert everything to these units The weight of one mole of H2O = 1.008*2 + 15.999 = 18.015 g 17.68 g ice = 17.68g * (1 m / 18.015 g ) = .981 moles ice = .981 mole H20 54.05 g water = 3 moles ...
*October 23, 2012*

**history 103**

Summarize the major factors that allowed the Incas to conquer and rule their large empire. Some suggest that, in many ways, the Incas were like the Romans or other Pre-Columbian American Civilizations. Evaluate whether they were more similar or different, and why. Make sure to...
*October 22, 2012*

**statistics**

0.5
*October 19, 2012*

**math**

Without the pass, the rider pays 2.00 * T With the pass the rider pays 17.25 + 1.25*T Set the two equal to each other, and solve for T 2.00 * T = 17.25 + 1.25 * T where T is the number of tickets
*October 17, 2012*

**Math**

S = 0.06(200,000 - 0.30(200,000 - S)) Start multiplying S = 0.06(200,000 - 60000 + 0.3*S) S = 12000 - 3600 + 0.018*S 0.982*S = 8400 S = 8554 F = 0.3(200000-8554) Solve for F
*October 17, 2012*

**physics**

The dimensions are irrelevant. F = m*g = 0.77 * 9.8
*October 17, 2012*

**Math**

(66 + 66 + 66 + x) / 4 = 70 Solve for x
*October 17, 2012*

**Math**

Each side will be multiplied by 1.25, so the total perimeter will be multiplied by 1.25 20*1.25 =
*October 17, 2012*

**Math**

(73.5 + 73.5 + x )/3 = 75 Solve for x
*October 17, 2012*

**math**

All three numbers must be factors of 60; 8 is not a factor of 60 so it can be excluded. The numbers left are 2, 4, 5, 6 You must take the three greatest to get a sum of 15: 4+5+6 = 15 and 60 is the GCF of 4, 5, 6
*October 17, 2012*