Saturday
December 3, 2016

Posts by Scott

Total # Posts: 1,550

Math
14 * 13 * 12 * 11 * 10 * 9 * 8 * 7 * 6 1st student has choice of 14 chairs ...2nd student, 13 chairs ... yada, yada
December 2, 2016

Maths
the horizontal component of P (along the rod) is [P * cos(30º)] the vertical component is [P * sin(30º)] the normal reaction is the block's weight (m * g), minus the vertical component of P you surmise correctly re: the result of P exceeding 392 Newtons
December 2, 2016

Interest
4000 * [1 + (.05 / 12)]^(5 * 12)
December 1, 2016

physics
1/2 * m * v^2 = 1/2 * .058 * 58 answer is in Joules
December 1, 2016

physics
a = f / m kg and N means m/s^2
December 1, 2016

Physics
? may be 3º ... the wording is ???
November 30, 2016

Algebra 2
good chioce
November 30, 2016

math
the 54th term is 50 differences from the 4th term
November 30, 2016

Math
m + n = 3 ... n = 3 - m m * n^2 = m * (3 - m)^2 ... = m^3 - 6 m^2 + 9 m the max appears to be infinite
November 30, 2016

Science
yes, gravity counts 22 / (10 * g)
November 30, 2016

Algebra 1 B
2 is good 3 needs work
November 30, 2016

physics
not sure about impossible... this is around escape velocity
November 29, 2016

physics
centripetal acc = v^2 / r ... v is the tangential velocity 16.7 = v^2 / 6.41E6 v / r = angular velocity (in radians)
November 29, 2016

algebra
n = 1000 * e^(.11 * 2)
November 29, 2016

Calculus
s(t) = -16t^2 + 1600 t the time of max height is on the axis on symmetry ... t = -1600 / (2 * -16) the slope of the tangent (1st deriv) is equal to zero at max height
November 29, 2016

geometry
looks like the line segment was doubled scale factor is two
November 29, 2016

science
molar mass of Bi is 208.98 g ... so there are 2 moles of Bi 6 moles of F will react to form BiF? the molar mass of F is 19.0 g add the mass of the Bi and the mass of the F to find the grams of BiF?
November 29, 2016

Chemistry
conservation of mass
November 29, 2016

Math
15.85 + .75 = 3n + 2(3.95) + 1.23
November 29, 2016

Math
1. n 2. 2n 3. 2n + 5 4. 100n + 250 ... moves chocolate times into hundreds place 5. 100n + [2016 or 2015] ... sets up #6 to yield age 6. 100n + age [(50[2(n)+5])+176?]-birth year
November 29, 2016

algebra
thanks for the catch, Reiny too late to be working on this stuff
November 27, 2016

algebra
(90 / c) + [130 / (c + 20)] = 4 90 c + 180 + 130 c = 4 c^2 + 80 c c^2 - 35 c - 45 = 0 use quadratic formula to find c
November 27, 2016

6 grade math area perimeter
area looks good perimeter might be 16 ... check it
November 27, 2016

6 grade math area perimeter
looks good
November 27, 2016

Physics
it accelerates for 4 s ... up to 8 rad/s then spins for 11 s ... 88 rad the ave vel during acceleration is ... ) + 8) / 2 = 4 rad/s ... spins 16 rad 104 rad total ... divide by 2? to find revolutions
November 27, 2016

calculus
the friend's distance north is 30 t your distance east is ... 40 - 20 t it's a right triangle use Pythagoras to find the hypotenuse ... which is the distance find the minimum - with respect to t
November 26, 2016

Physics
the centripetal force (m v^2 / r) is equal to the gravitational force ... G M m / r^2 v^2 = G M / r ... = 6.67E-11 * 5.98E24 / 7.12E6 the period is the speed divided into the orbital circumference
November 26, 2016

Physics , static fluids
the ice is 92% as dense as the water so 92% of the block is submerged when it floats that leaves 8% exposed
November 26, 2016

Algebra
s + L = 40 s + 6 = L subtracting the equations ... eliminating s L - 6 = 40 - L
November 26, 2016

Physics
the supports each exert 98 N to support the plank one support exerts [490 N * m / 3] to support the person the other support exerts ... 490 N - [490 N * m / 3]
November 26, 2016

Physics , static fluids
the buoyancy force is the difference in the air weight and immersed weight
November 26, 2016

Physics , static fluids
hello (again) 8.6 meters is 860 cm if you picture a stack of 860 cm cubes of water, what is the force at the bottom? ... 860 gm * g ... this is the force on one cm^2 .86 kg * 9.8 m/s^2 = f a Pascal is one Newton per m^2 ... a kPa is .001 N per cm^2
November 26, 2016

Physics
you can use the density of water and the depth to find the pressure the "rule of thumb" for diving is one atmosphere for every ten meters of depth
November 26, 2016

Physics
e = 1/2 k x^2 ... (kind of like KE) 2.0 = 1/2 * 100 * x^2
November 25, 2016

Physics
look up Doppler shift formula
November 25, 2016

Maths
2 = (1 + .06)^t log(2) = t log(1.06) t = [log(2)] / [log(1.06)]
November 23, 2016

Algebra 2 (Please help Ms. Sue!)
use synthetic division
November 23, 2016

Algebra
(d / 55) + (d / 35) = 50 - 10
November 22, 2016

Physics
momentum is conserved find the momenta in x and y for the two decay products the two y momenta add to zero, and the two x momenta equal the original add the vectors to find the 234Th velocity
November 22, 2016

pre calc
100% - 30% = (1/2)^(2 / h) log(.7) = (2 / h) log(1/2) h = 2 log(1/2) / log(.7) (after a week) = (1/2)^(7 / h)
November 22, 2016

Algebra
it stops at the top, so the average velocity is ... (103 + 0) / 2 gravitational acceleration is 32 ft/s^2 , downward so the time to reach the peak is ... 103 ft/s / 32 ft/s^2 r * t = d
November 22, 2016

Physics
momentum is conserved, so the truck's loss is the car's gain 7500 kg-m/s / 750 kg = ?
November 22, 2016

physics
radio waves travel at the speed of light (c) ... 3E8 m/s the distance from Venus to Earth depends on where each planet is in its orbit around the Sun
November 22, 2016

technical drawing
85 m is 85000 mm 85000 mm / 10000 = ?
November 22, 2016

science
x + y = 10 3.1 x + 2.5 y = 25 solves easily by inspection (observation)
November 21, 2016

physics
6000 Nm/s = 6 kw
November 21, 2016

Physics
the object displaces 1/5 of its weight in water, so it is 5 times the density of water the weight change in the other liquid is 2/3 of the change in water, so the other liquid is 2/3 the density of water
November 21, 2016

Chemistry
the Ar will effectively be "squeezed" into 80% of its previous volume this will increase the tank pressure to 125% of the original the pp of Ar is 80% of the total the pp of nitrogen is 20%
November 20, 2016

Physics
F accelerates the three boxes equally since C is half of the total system mass, F equals twice the force on C
November 20, 2016

physics
the initial vertical velocity is ... 50 m/s * sin(37º) the (vertical) freefall equation is . h = 1/2 g t^2 + [50 sin(37º)] t + 55 plug in zero for h (ball on ground) and solve for t (use quadratic formula) the horizontal velocity is ... 50 m/s * cos(37º) ... ...
November 20, 2016

math
the intercepts are points with x and y coordinates for x-intercepts, the y coordinates are zero...but they still exist
November 20, 2016

Physics
avg vel = (14 + 0) / 2 = 7 rev/s stop time = 1/7 s distance = 1/2 a t^2 ... 1 = 1/2 * a * (1/7)^2
November 20, 2016

Maths
6 pts total per event 24 pts total awarded...so 4 events Betty has three 1st's and a 2nd Cathy has a 2nd and three 3rd's
November 20, 2016

physics
momentum (as usual) is conserved .05 * v = (5 + .05) * 10
November 17, 2016

applied physics
g = -980 cm/s^2 the object reaches its peak at 2 s average velocity is 980 cm/s ... so peak height is 1960 cm time up equals time down
November 16, 2016

Physics
KE = 1/2 m vB^2 6 KE = 1/2 * m/2 * vA^2 12 = (vA / vB)^2
November 16, 2016

Physics
twice the force, twice the stretch
November 16, 2016

Math
what design?
November 16, 2016

Algebra
the general equation is ... x = a(y - k)^2 + h the vertex is at the origin, so h and k are both zero a = 1 / 4p ... where p is the distance from the vertex to the focus b) the center depth is the value of x at the edges of the dish (where y equals ±7)
November 16, 2016

Physics
the acceleration (j) of the jet and gravitational acceleration (g) are two sides of the triangle j / g = tan(25º) ... j = 9.8 m/s^2 * tan(25º) multiplying j by 11 s will give the takeoff speed
November 16, 2016

Psychics
d = 1/2 a t^2 88.3 = 1/2 * 23.6 * t^2
November 16, 2016

Math
your "weird" answer is correct
November 15, 2016

Math
An = [10 * 3^(n-1)] + 1
November 15, 2016

Technology
the moments about the fulcrum must be equal for balance moment = mass * distance from fulcrum
November 15, 2016

university physics
momentum is conserved with the pellet/block find the velocity of the pellet/block the KE of the p/b is the work that compresses the spring 1/2 m v^2 = 1/2 k x^2
November 15, 2016

Differential calculus
the general vertex form is ... y = a(x - h)^2 + k ... (h,k) is the vertex a = 1 / 4p ... p is the distance from the directrix to the vertex
November 14, 2016

Trig
use Pythagoras (a^2 + b^2 = c^2) to find the angle functions then use the trig identity to find the tangent
November 14, 2016

Advanced physics
the period of the swing (pendulum) is related to its length the speed is not a factor
November 13, 2016

Algebra
a = 2 b 3(a + b) = 90
November 13, 2016

Chemistry
an interesting question will probably make for a lively class discussion a couple of pertinent facts ... normal exhaled air is about 15% O2 ... humans can "survive" in air down to about 6% O2
November 13, 2016

Physics
the work (energy) is equal to the KE of the object f d = 1/2 m v^2 123 * 45.6 = 1/2 * 10.0 * v^2
November 13, 2016

Maths
12 ... 4/10
November 13, 2016

Math (Derivative)
a) y = 6 x^-1 ... dy/dt = -6 x^-2 dx/dt ... dy/dt = (-6 / 64) * 12 b) missing y a typo?
November 13, 2016

Math
p(p + 1) = 3192 p^2 + p - 3192 = 0
November 13, 2016

Science
yes certainly if 180º apart
November 12, 2016

Physics
work (energy) to stop the wagon ... w = 42 * g * .18 * 16 w equals the initial KE of the wagon ... 1/2 * 42 * v^2 = w the speed of the boy is the same as the initial speed of the wagon
November 12, 2016

Chemistry
you are correct
November 12, 2016

Maths
eight "3" cards gives 24 ... 7 shy of 31 replace four "3" cards with three "5" cards and a "4" card
November 11, 2016

Physics
d = 1/2 a t^2 t = ?(2 * d * a)
November 11, 2016

Physics
the period (of the pendulum) is dependent on the length the speed of the "bob" is not a factor
November 11, 2016

math- Trigonometry
looks good...TALL lighthouse
November 11, 2016

Chemistry
.325 L * .05 M/L * 55.8 g/M
November 11, 2016

Math
time is inversely proportional to the number of machines and directly proportional to the number of raviolis t = 15 min * 15/75 * 6000/500
November 11, 2016

science
would call this a "trick" question circular path means radial (centripetal) acceleration there is no tangential component
November 11, 2016

Math
d = 6 233 - 53 = 180 ... so, 31 terms s = (233 + 53) * 31 / 2
November 10, 2016

Physics
1 kcal = 4184 joules m g h = 300 * 4184 h = (300 * 4184) / (1000 * g)
November 10, 2016

Physics
the gravitational potential energy becomes kinetic energy m g h = 1/2 m v^2 v = ?(2 g h)
November 10, 2016

Physics
20º is 1/18 of a circle (20/360) the length of the arc is ... 1/18 * 2 * ? * 1 m
November 10, 2016

Physics
momentum is conserved the smaller mass is 1/3 of the larger ... so it must have 3 times the speed
November 10, 2016

Math
check the related questions
November 10, 2016

Physics
f = m a ... a = f / m a = (33 - 12) / (6 + 15)
November 10, 2016

physics
time up equals time down h = 1/2 g t^2 = 1/2 * 32 ft/s^2v * (2 s)^2
November 10, 2016

math
the x-coordinate doesn't change the sign of the y-coordinate is reversed drawing a picture can help
November 9, 2016

Math
complex roots (zeros with i) occur in conjugate pairs f(x) = (x-6+3i)(x-6-3i)(x^5)
November 9, 2016

math
i = 7400 * [1 - (1 + .06/4)^(4*4)]
November 9, 2016

algebra
try again on the 1st one the slope formula does work
November 9, 2016

physics
the frictional force is ... 5 * 9.8 * .4
November 9, 2016

Physics: Centre of Mass
(4 * 4) + (8 * 5) > 7 * 5 ... so the CM is > 0 [4*(4-x)]+[5*(8-x)]-[7*(5+x)] = 0
November 8, 2016

Math
Tom has a 40 km head start ... 80 km/h * .5 h Cindy is catching up at 20 km/h ... 100 km/h - 80 km/h
November 8, 2016

Physics
the velocity is the vector sum of the horizontal and vertical components horizontal ... 88 m / 3.8 s vertical ... time up equals time down ... (3.8 s / 2) * 9.8 m/s^2 the max height is half the initial vertical component, multiplied by half the flight time
November 8, 2016

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>