Friday
July 29, 2016

Posts by Scott

Total # Posts: 1,130

Gen Chem
Knowing the MW of salicylic acid (138.12g/mol), design a procedure to make 100mL of a 0.0050M salicylic acid solution.
May 20, 2016

General Chemistry
That's why I was confused, it just states that the Fe(OH)3 has a solubility product of 10^-39. Any ideas?
May 20, 2016

Organic Chemistry
When I solve for Fe I get 1.75mL and for SYL I get 210mL. That can't be correct if we are trying to make 50mL. The equation is: Salicylic Acid + [Fe(H2o)6]^+3 ---> Iron-salicylate complex
May 20, 2016

Grade 12 Calculus and Vectors
Thank you very much Steve.
May 17, 2016

Grade 12 Calculus and Vectors
A homeowner wants to enclose a rectangular garden with fencing The garden will be adjacent to his neighbours lot. There will be fencing on all four sides. His neighbour will be paying for half of the shared fence. What should the dimensions of the garden be if the area is 432 ...
May 17, 2016

Pre-Calculus
Okay, what point is your origin? Normally it is (0,0) but not always...
May 17, 2016

Math
no C.
May 14, 2016

math
5C3 = 10
May 14, 2016

math
substituting -x + 13 = x² + 6 x + 7 0 = x² + 7 x - 6 none of the answers are correct
May 14, 2016

Math
.25 t = 1 t = 1 / .25
May 14, 2016

math
A - 25 = B + 25 ... A - 50 = B 7(B - 100) = 2(A + 100) ... 7 B - 700 = 2 A + 200 ... 7 B = 2 A + 900 substituting ... 7(A - 50) = 2 A + 900 ... 7 A - 350 = 2 A + 900 ... 5 A = 1250 ... A = 250
May 14, 2016

SCIENCE
pressure is force per unit area 100 N / 25 cm² = 4 N/cm² the SI pressure unit is the pascal 4 N/cm² = 40000 N/m² = 4 kPa
May 14, 2016

Maths -Logarithm
3^3 = 27 log(x) = 27 log(3) x = 10^[log(x)]
May 14, 2016

geometry
hard to tell without the diagram
May 14, 2016

algebra
(a) 37% / 60% (b) 37% / 52%
May 7, 2016

Physics
momentum is conserved m bt * v bt = (m bt + m bk) * v bkbt h = ½ g t² ... 1.3 = 4.9 t² ... t = .52 s v bkbt = d / t = 2.2 m / .52 s ... v bkbt = 4.2 m/s 7 * v bt = 131 * 4.2
May 7, 2016

probability help!!
all wait times have an equal probability so the probability of being in any one of three five-minute intervals is ⅓ (a) is the 1st interval (b) is the last interval
May 7, 2016

Math
the slant height is the height of the triangles that make up the sides of the pyramid the base of the triangles is the base side length pentagonal means five triangular sides with a height of 18 and a base of 9 find the areas and add them up (or find one and multiply by 5)
May 6, 2016

math
a = 6350 [1 + (.14 / 2)]^[12 / (1/2)]
April 19, 2016

physics
the acceleration is ... 2 m/s / 14 s = .14 m/s² as the car goes up a slope, the gravitational acceleration on the car is proportional to the sine of the angle of the slope sin(Θ) = .14 m/s² / 9.8 m/s² = .014 Θ = 0.8º
April 19, 2016

Math
Given function 3x/x^2-x-12 sub in -1 for x. I get the value x=0.3. Is that right?
April 16, 2016

ph science
work = 64 N * cos(35º) * 45 m
April 16, 2016

Physics
A 0.11-kg balloon is filled with helium (density = 0.179 kg/m3). If the balloon is a sphere with a radius of 5.4 m, what is the maximum weight it can lift?
March 28, 2016

Algebra
A man paid $7.80 for 5 The grams of peanuts and 3 kg of walnuts. Walnuts are $.20 a kilogram more than peanuts how much did she pay per kilogram for each
March 21, 2016

home school
In which of the following are 1/2,5/6, and 5/8 arranged in ascending order?
March 13, 2016

Math Question
Write the fraction below as a decimal. 7 --- = 100
March 8, 2016

phy 231
at the equilibrium position, there is no energy stored in the spring, it's all in the kinetic energy of the block KE = 1/2 m v²
March 8, 2016

Physics
vertical ... 2[5 sin(θ)] / g = t ... h = 5/2 sin(θ) * t/2 horizontal ... d = 5 cos(θ) t 2h = d 5/2 sin(θ) t = 5 cos(θ) t dividing by cos(θ) t and multiplying by 2/5 tan(θ) = 2 substitute back to find t
March 7, 2016

Physics
time up equals time down flight time = 2 * 30 m/s / 10 m/s²
March 7, 2016

Physics
there are 3600 s in an hr 180 km/h = 50 m/s the average velocity during the stop is ... (50 + 0) / 2 the stopping distance is ... 25 m/s * 20 s
March 7, 2016

Physics
gravity decelerates the ball time to peak is ... 30 / 9.8 the velocity at peak is zero, so the average velocity is ... (30 + 0) / 2 peak height is average velocity, multiplied by time
March 7, 2016

Physics
it's a 3-4-5 triangle 600-800-?
March 7, 2016

Math
If a pie was cut into sixths and one cut into eighths how many pieces are there altogether?
March 5, 2016

Statistics
the upper 15% of weights are a little over one S.D. above the mean so, more than ... 764 + 33 using a z-score table ... 1.036 S.D so, more than ... 764 + (33 * 1.036)
February 29, 2016

Chemistry
-log[H⁺] = 5.42 ... [H⁺] = 10^-5.42 = 3.80E-6 Ka = [H⁺][A⁻] / [HA] ... = 3.80E-6 * 3.80E-6 / ... (.095 - 3.80E-6) ... = ?
February 29, 2016

Science
electricity
February 29, 2016

Physics
momentum = m v = .057 * 29 the units are kg·m/s
February 25, 2016

Algebra
completing the square (16 / 2)² = 64 (x + 8)²
February 25, 2016

Chemistry 101
400 T * 1.0 oz/T * $1625 / oz
February 25, 2016

Math
s^2 = (6/2)^2 + 5^2 pick another letter
February 24, 2016

Geometry
factor the numerator [n * (n + 1)] / 4 n cancel the n in the numerator and denominator (n + 1) / 4
February 24, 2016

physics
conservation of momentum (again) (2300 + 1290) * 4800 = (1290 * 5600) + (2300 * v)
February 23, 2016

physics
momentum is conserved (a) 98 * 3.2 = 235 * -v (b) 98 * 3.2 = (98 + 235) * v
February 23, 2016

Algebra 2
you have the hypotenuse and the side lengths use trig functions to find the two unknown angles (A and B) S-O-H-C-A-H-T-O-A
February 23, 2016

MATHS
7 P + 22 = 2 (5 P + 2) 7 P + 22 = 10 P + 4 18 = 3 P
February 23, 2016

STATISTIC
you are right
February 23, 2016

Physics
the car is overtaking the truck the relative speed is 30 mph ... the distance is closing ... that's why the Doppler frequency is higher apparent frequency = actual frequency * [(speed of sound) / (speed of sound - closing speed)]
February 23, 2016

physics
f = m a μ m g = m (d / t²) μ = (d / t²) / g = (1320 / 6²) / 32 the assumption is that all of the mass acts on the driving wheels
February 22, 2016

math
Solve for all real values of y: |3y+7|=|2y-1|.
February 21, 2016

physics
when it leaves the roof vertical velocity ... -7.00 sin(40º) horizontal velocity ... 7.00 cos(40º) the horizontal velocity is constant the vertical velocity is increased by gravity (acceleration) h = -1/2 g t² + v₀ t + h₀ ... t is the time of flight ...
February 21, 2016

physics
m g h = 1/2 m v² h = v² / (2 g)
February 20, 2016

Physics
the drop height is ... 1/2 g t² the times are ... 4 s ... and (4 - 2.34) s g is ... 9.81 m/s² fire up that calculator
February 20, 2016

Trig
a road is inclined at an angle of 45degrees. After driving 300 feet along this road, find the driver's increase in altitude.
February 19, 2016

Ms. Sue, please help me on math!
they are both correct
February 18, 2016

Physics
an Ampere is a Coulomb per second a Coulomb is the charge on 6.242 x 10¹⁸ electrons there are 3600 seconds in an hour .497 * 6.242E18 * 3.6E3 = answer
February 18, 2016

Algebra
they each do a fraction of the job the fractions add to one the whole job (2.2 / T) + (2.2 / J) = 1 substituting [2.2 / (J + 2)] + (2.2 / J) = 1 solve for J, add 2 to find T
February 18, 2016

Chemistry
yes, but they give you the wavelength e = h c / λ make sure your units are consistent
February 18, 2016

Chemistry
2 moles of Al to 3 moles Cl₂ use the molar masses to find the number of moles
February 18, 2016

physics
the decimal point on the mass units is incorrect Joules uses kilograms, not grams you used kg in the momentum, but not the K
February 17, 2016

Physics
in the vertical direction ... h = 1/2 g t^2 + 59 sin(32º) t in the horizontal direction ... d = 59 cos(32º) t use the axis of symmetry of the parabola to find the time for max height plug the time into the vertical equation to find the max height the initial energy ...
February 17, 2016

physics
momentum is conserved 71 * 2.5 = 59 * v the direction is negative x
February 17, 2016

chemistry
the molar mass of water is 18.0 g E = [25 * (100 - 25) * .00418] + ... [(25 / 18) * 40.6]
February 17, 2016

science, chemistry
100.0 mL * 12.0 M = v * 5.20 M
February 17, 2016

Math
7 * 1/12
February 17, 2016

6th grade math median range mode
if all the values occur equally, there is no mode
February 17, 2016

Physics
the acceleration is ... (5.31 - 1.25) / 1.05 the sine of the angle of inclination is equal to the actual acceleration divided by gravitational acceleration sin(Θ) = [(5.31 - 1.25) / 1.05] / g
February 17, 2016

Algebra
z + t + c = 1000 t = 2 z c = 15 t + 10 = 30 z + 10 z + 2z + 30z + 10 = 1000 solve for z, then substitute back to find c and t
February 17, 2016

Chemisty
a mole is Avogadro's number ... 6.02 x 10^23 so you need the mass of a third of a mole of F₂ the molar mass of F₂ is 38 g
February 17, 2016

Math question/help please!
the letters correspond to the vertices K and P are congruent as are M and R and L and Q MK and ML are sides ...not measured in degrees just post the size of any of the angles that are given
February 17, 2016

science
this is a time/temperature plot the line slopes up from 35 to 75 while the solid warms up the line levels off at 75 while the solid melts phase change the line slopes up from 75 to 126 while the liquid warms up the line levels off at 126 while the liquid boils phase change the...
February 17, 2016

Chemistry
sorry...should be 2 H₂
February 16, 2016

Chemistry
Ca is a +2 ion so 2 OH (just like the 2 H) CaH₂ + 2 H₂O --> Ca(OH)₂ + H₂
February 16, 2016

Physics
gravitational potential energy is converted to kinetic energy m g h = 1/2 m v² 9.8 * 1.8 = v² / 2
February 16, 2016

physics
the vertical launch velocity is ... 33 sin(12º) 0 = 1/2 g t² + [33 sin(12º)] t + 23 use the quadratic formula to find t ...you want the positive solution g = 9.8 m/s²
February 16, 2016

chemistry
the spectrum is the result of hydrogen's electron transitioning between energy levels the levels are fixed ... quantized (per bob)
February 16, 2016

Chemistry: stoich
molar mass of O₂ is 32 g 5 moles O₂ yields 4 moles H₂O
February 16, 2016

Chemistry
answered
February 16, 2016

physics
momentum is conserved x-component ... -8.80 [4720 / (4720 + 1180)] y-component ... -1.45 [1180 / (1180 + 4720)] v = √(x^2 + y^2) the tangent of the reference angle in quad III is ... y/x
February 16, 2016

Chemistry
the molar mass of O₂ is 32 g 3 moles of oxygen produce 2 moles of iron oxide (2.50 / 32)* 2/3 = moles of Fe₂O₃ the molar mass of Fe₂O₃ is 159.7 g
February 16, 2016

Math HELPP!!
obtuse? that means an angle greater than 90º B is correct
February 16, 2016

Math HELPP!!!!
correct
February 16, 2016

Math. PLZZZ HELP ME!!!
or B or C... not enough info in the question TOO GENERAL
February 16, 2016

Math. PLZZZ HELP ME!!!
a quadrilateral with opposite sides equal and parallel is a parallelogram the 1st three answers are various types of parallelograms a trapezoid is not
February 16, 2016

Science
the same side of the moon always faces the Earth because the moon's rotational period is equal to its orbital period if the moon had a rotational period different from its orbital period, then different sides of the moon would be facing the Earth at different times
February 16, 2016

Physics
the horizontal component of the force is... f cos(Θ) as you say... a = [f cos(Θ)] / m
February 16, 2016

Physics
no friction, so why is gravity involved? f = m a 89 = (8 + 33 + 49) a
February 16, 2016

Physics
so the maximum load (cabin plus cargo) is 3300 kg the tension is the force that will accelerate the load to .68 m/s² this is against gravity so the tension overcomes gravity (mg) PLUS accelerates the load t = m g + m a = m (g + a) ...= 3300 (9.81 + .68)
February 16, 2016

physics
work (energy) is equal to the product of the force and the distance the energy is the same for both
February 16, 2016

AP Physics 1
.12 * 5.0 * 20.0 * 220 / 1000 A * V = watts watts * 5 = watt·hr dividing by 1000 gives kw·hr
February 16, 2016

physics
constant velocity means zero acceleration f = m a f = m * 0 f = 0
February 16, 2016

Math
5280 feet in a mile 12 inches in a foot the long skinny right triangle base = half mile hypotenuse = half mile plus half inch height = √(hypot^2 - base^2) almost 15 feet
February 15, 2016

chemistry
the reaction equation is in moles so you need to convert grams of iron oxide to moles the molar mass is 159.7 (two iron plus 3 oxygen) 14.7 g / 159.7 g/mol = .092 moles the reaction equation shows 3 moles of carbon dioxide for each mole of iron oxide so .092 * 3 = .276 moles ...
February 15, 2016

URGENT! Due soon and I used 8 of 10 attempts
be careful of significant figures,,,
February 14, 2016

URGENT! Due soon and I used 8 of 10 attempts
.5^n = .145 n = log(.145) / log(.5) = 2.786 2.786 * 5730 = 1.60 x 10^4
February 14, 2016

Physics
so M2 hangs over the side? f = m a ... a = f / m ... the blocks have the same a (g - t) / M2 = t / M1
February 14, 2016

Math
volume of water is volume of pyramid minus the volume of pyramid above the water v = 480 - 480 (1 - d/10)² ...= 480 - 480 (1 - d/5 + d^2/100) ...= 96 d - 4.8 d^2 dv/dt = 96 dd/dt - 9.6 d dd/dt 2 = 96 dd/dt - 9.6 * 4 * dd/dt 2 = 96 dd/dt - 38.4 dd/dt closer than .0496, but...
February 14, 2016

Algebra
"trick" question the cosine of the complement equals the sine of the angle
February 14, 2016

Calculus
the description is of a hemisphere of radius 3 v = 2/3 π r³
February 14, 2016

Chemistry
density = mass / volume volume = mass / density v = 2.0E3 g / .785 g/mL = 2.5E3 mL careful with your units the mass is only 2 sigfig
February 14, 2016

chemistry
E = h * (c / λ) energy = Planck's constant * speed of light / wavelength λ = h * c / E h = 6.63E-34 J·s λ = 6.626E-34 * 2.998E8 / 3.211E-19 λ = 6.186E-7 m = 618.6 nm
February 14, 2016

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