Monday
June 27, 2016

Posts by Scott

Total # Posts: 972

MATH
the radius, distance, and half the chord form a 5-12-13 triangle
June 5, 2016

MATH
the radius, half the chord, and the distance form a 3-4-5 triangle
June 5, 2016

chemistry
the sodium is the limiting reactant .6 moles
June 5, 2016

Math
[(76 - x) / 4]² + (x / 4)² = 205 76² - 152 x + x² + x² = 205 * 16 use the quadratic formula to find x either x or 76-x is shorter
June 5, 2016

math
s² < 6 s ... s < 6 any square with a side length less than 6
June 5, 2016

Chemistry
the estimated mass is to high (positive error) the amount is 10/240 ... A
June 5, 2016

chemistry
close ... D the decimal point makes the trailing zero significant
June 5, 2016

Math
when you connect the midpoints, the triangle formed is half the perimeter of the original triangle
June 4, 2016

gen chem
looking at the formula, there are two hydrogens for every carbon so ... 4.06x10^21 atoms of hydrogen there are 6 carbon atoms in each glucose molecule, so the number of molecules is ... 2.03x10^21 / 6
June 4, 2016

Math - Year 10 - Simult. Equations
o + t = 21 1 o + 2 t = 30 subtracting equations t = 9
June 3, 2016

Maths - Year 10 - Simult. Equations
50 f + 20 t = 310 f + t = 11 ... 20 f + 20 t = 220 subtracting equations (to eliminate t) 30 f = 90 ... f = 3 substitute back to find t
June 3, 2016

math
104² - 40² = x²
June 3, 2016

advanced science
net force is ... 1860 - 480 the acceleration is the net force divided by the mass significant figures appear to be a factor (Hint: there are two)
June 3, 2016

advanced science
the normal force is the force perpendicular to the load bearing surface...it is equal to the weight of the load on the surface in this case ... m * g the force is upward from the surface
June 3, 2016

physics
one
June 3, 2016

Physics - Doppler Effect
the frequency is lower, so the car is moving away from the listener 875/900 = (speed of sound) / ... (speed of sound + speed of car) they give you the temperature so that you can find the speed of sound (in air)
June 2, 2016

chemistry
.6 is correct ... due to H⁺ activity
June 2, 2016

math
law of cosines x² = 127² + 64² - [2 * 127 * 64 * cos(90º + 38º)]
June 1, 2016

Physics
answered yesterday
June 1, 2016

Chemistry
HCl totally dissociates, so the hydrogen ion concentration is .002 M pH = - log[H⁺] = - log(.002)
June 1, 2016

Chemistry
the volume increased by a factor of 2.5 the volume is directly proportional to the absolute (Kelvin) temperature ºK = ºC + 273
May 31, 2016

math
30 / 50 = 3 / 5
May 31, 2016

Physics
d = 1/2 a t²
May 31, 2016

physics
your distances from the speakers are different by a half wavelength (this is the reason for the sound "cancelling") 14 - 5 = 11 so the sound wavelength could be 22 ft
May 31, 2016

Physics
it takes ... 24 m/s / .65 m/s² to stop the average velocity is ... (24 + 0)/2 the stopping distance is the product of time and velocity
May 31, 2016

Physics
the component of the force that moves the crate (horizontal) is...the applied force, multiplied by the sine of the angle to the component 10N * sin(45º)
May 31, 2016

chem
the partial pressure is the total pressure, multiplied by the fraction of the gas involved in this case ...ppO = .32 * 132 atm ...ppN = (1 - .32) * 132 atm
May 30, 2016

SCIENCE
the 2nd one
May 28, 2016

PHYSICS
downward velocity at impact ... v = √(2 * 10 * 20) = 20 m/s upward velocity after impact ... v = √(2 * 10 * 15) = 10√3 m/s accel = Δv / t = (20 + 10√3) / .01 ...units are m/s²
May 28, 2016

College algebra
100 + 5 x = 103 + 4 x
May 26, 2016

Algebra
2.75 < 2.25 + (750 / p) < 3.75 .50 < 750 / p < 1.50 2 > p / 750 > 2/3 1500 > p > 500 none of the responses seem to be correct
May 26, 2016

age problems(please help)
S = 3s ... t = 5S = 15s t + 5 = 5(s + 5) = 5s + 25 3t + 15 = 15s + 75 substituting ... 3t + 15 = t + 75 solve for t
May 25, 2016

Physical Science
heat the ice to 0º melt the ice heat the water to 20º look up the heat of fusion for ice and the specific heats for ice and water
May 25, 2016

physics
the distance is closing, so the frequency is higher F = 50kHz * [1450 / (1450 m/s - 450 km/hr)]
May 25, 2016

Calc-Math
you need to use the product rule for xy x dy/dt + y dx/dt
May 24, 2016

Physics
its average speed while stopping is 30 mi/h there are 3600 sec in an hr , and 5280 ft in a mi d = 30 * 5280 * 6 / 3600 ... feet
May 24, 2016

Math
10 = 1/2 * g * t^2 20 / 9.8 = t^2
May 24, 2016

math
The area if a rectangle is x3y4. Which expression represents the length if the width is x2y
May 24, 2016

physics
C = Q / 100...100 C = Q capacitors add in parallel the charge is the same (redistributed) C + 10 = 100 C / 30 solve for C
May 24, 2016

Math
C. The answer is C, -7.
May 24, 2016

Math
It is impossible. 12, 14, or 16 may work, but I think you should give up on this equation...
May 24, 2016

Gen Chem
Thank you DrBob222!
May 20, 2016

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

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