# Posts by Scott

Total # Posts: 2,320

Math
the outside diameter is 8 ft more than the inside ? times 8 ft is about 25 ft 802 is WAY high

precal
it takes a second for the coin to reach max height, 16 ft above the balcony d = 1/2 a t^2 346 - 90 = 1/2 g t^2 solve for t, add in the 1st second

Math
50 cm * ? * 25

Physics
the deceleration is ... (13.0 -10.9) m/s / 2.20 s ... slightly less than 1 m/s^2 so it takes about 13 s to stop ... during which the average speed is ... (13.0 + 0) m/s / 2

Science
f = m a ... w = m g ... m = w / g

Physics
1/2 m v^2 = m g h h = v^2 / (2 g)

algebra
the question asks about "carriers" (like the RL parent) what percent is like the RL parent?

math
2 equations and 2 unknowns, just solve the system by substitution or elimination

math
looks good

algebra
the distance is the hypotenuse of the right triangle ... use Pythagoras

Algebra
the max A lies on the axis of symmetry Wmax = -b / 2a = -200 / (2 * -2) = 50

calculus
the quadratic solutions are relative max/min points on the graph (you obviously want the max) test the solutions in the original equation x < 4 because of the 8 in side

maths
the reflection is along a line through the center of the circle, perpendicular to the given line slope of perpendicular is ... -1 equation of perpendicular ... y-3 = -1 (x-2) ... y = -x + 5 intersection with reflecting line ... (1,4) center of reflected circle ... (0,5) center...

Math
subtract 8 ... -m/5 > 2 multiply 5 ... -m > 10 divide -1 ... m < -10

Gr 12 Data
a) 2^5 c) 2^3 ... arrangements of 3 middle coins d) 2^2 ... arrangements of 2 end coins e) yes , a coin toss is a coin toss

science
the masses are inversely proportional to the heights ... higher height means lower mass Hb Mb = Hj Mj

geometry
the general equation is ... (x - h)^2 + (y - k)^2 = r^2 r is the radius , (h,k) is the center

Statistics
25 people bought 35 cones so 10 people bought both 5 only van - 10 both - 10 only choc

geometry
(x - h)^2 + (y - k)^2 = r^2 the equation defines a circle of radius, r; centered at (h,k)

math
? rs = 20 b ... 1.1 ? rs = 22 b ? rs = 22 (b - .25) + .20 = 22 b - 5.3 .1 ? rs = 5.3 ? = 53

Maths
adding 5 ... | x | > 11 x < -11 , x > 11

Math
looks like #5

Math
how many are what age?

math
it's a 5-12-13 Pythagorean triple

Math
remember the hierarchy of operations ... PEMDAS adding 5 ... c/4 = 9 multiplying by 4 ... c = 36

word problem
Ar + Au + D + B = 267 Ar = Au - 8 D = 2 Au B = 5 Au + 5 substitute in the 1st equation to find Au ... then substitute back to find the others

Math
looks good

Physics 20
p1 exerts the same force on p2 that p2 exerts on p1 f = m a ... m1 a1 = m2 a2

Science
rethink #2

algebra
subtracting 5 shifts the 1st function 5 units down to give the 2nd function

binomial distribution
(s + f)^5 s^5 + 5 s^4 f + 10 s^3 f^2 + ... 10 s^2 f^3 + 5 s f^4 + f^5 s = p(success) = .687 f = p(failure) = 1 - p(success) = .313

Math
the terms are getting larger ... diverging

graphing help?
there is a website called fooplot you should use it

Bio chem
How many mL of 0.80 molar NaOH must be added to 20 ml of 0.40 of molar propionic acid, in order to produce a solution with a pH of 4.89? (PKa of propionic acid is 4.89.)

consumer math
2000 (1 + .08)^6

math
85000 + [(39637 - 35416) / .45]

Physics
boat components ... W ... 25 cos(35º) = 20 ... N ... 25 sin(35º) = 14 add the boat components to the current (14 N + 18 S) + 20 W = 20 ... the tan of the angle is ... S/W ... arctan(4/20) = 11º ... [W11ºS]

Math
the trip times are not the same, so the average speed is not 9 mph sorry, Ms. Sue

Math
d = r t ... t = d / r 27/60 = (d / 10) + (d / 8) 54/120 = (12 d / 120) + (15 d / 120) d is the distance to the lake

Math
get all the equations into slope-intercept form (y = mx + b) 1. the slopes are the same but the intercepts are different ... the lines are parallel ... they never intersect so no solution 2. the slopes are the same and so are the intercepts ... the lines lie on top of each ...

Math, Algebra
(2s + 5)(s - 6) = s^2 2s^2 - 7s - 30 = s^2 s^2 - 7s - 30 = 0 (s - 10)(s + 3) = 0

trig
Upper? plane ... N component ... 450 kph cos(45º) ... E component ... 450 kph sin(45º) wind ... N component ... 60 kph cos(30º) ... W component ... 60 kph sin(30º) add the components to find the resultant vector

math
it's four times as tall in the picture, so it's four times as tall in real life

Math
p + g = 20 4p + 2g = 70 solve the system using substitution or elimination

10 ft long and 4 ft wide is 40 ft^2

Algebra
4 w + 2 k = 62 w + k = 21 solve using substitution ... or elimination

physics
centripetal force is ... m v^2 / r a) (2 ? r) / 6.10 m/s b) m [g - (v^2 / r)] c) m [g + (v^2 / r)]

Physics (I have a test tomorrow)
the average speed of the car is 50 kph convert the speeds to m/s find the time to cover the 85 m find the change in kinetic energy ... KE = 1/2 m v^2 the work against resistance (friction) ... work = f d = 750 N * 85 m work and energy are the same thing add the work and the ...

Physics
the forces in c and d are normal (perpendicular) to the direction of motion of the car they do no work

physics problem
(2 * ? * 34 cm) / 39 m/s watch your units

Science
correct why the confusion?

Science
sounds like fermentation if there is oxygen, you get vinegar instead of wine

math
a- A = 12000 [1 + (.039/12)]^(6 * 12) b- subtract 12000 from a-

maths
no the ratio between the sides is not equal

math
A does 4/60 and B undoes 3/60 so 1/60 completed every 2 days after 112 days, 56/60 are done ... A completes the work on the 113th

algebra
6C3 ... 6! / (3! * 3!)

Math
it's a system of equations 5 V + 3 C + 2 M = 675 V = 2 C M = C + 75 substitute and solve

Math
x = 6 * 2^n

physics
cool the steam to 100ºC condense the steam cool the water to 0ºC freeze the water two specific heats heat of vaporization, and heat of fusion

Math
(300 / 500) * 250,000

Physics 1401
the center of mass of the stick is at the 50 cm mark ... 10 cm from the balance point the 6 g is 30 cm from the balance 10 * m = 30 * 6

Physic sucks 1401
the masses are linked by the string and have the same acceleration ... one upward and the other downward f = m a ... a = f / m (t - m1 g) / m1 = (m2 g - t) / m2 2t - 2g = 2g - t ... 3t = 4g ... t = 4/3 g the largest mass is 2 kg ... it gives about 20 N of force with the system...

Geometry Proofs
My teacher said she gave us everything.

Geometry Proofs
Trying to solve a proof. Triangle ABC. D is a point on side AC and E is a point on side BC. There is a line from Angle B to Point D and a line from Angle A to Point E. My Givens are AD = BE and BE>AE. I need to prove BC>AC. This is for my 7th grade geometry class. Thank ...

Chemistry
no some are not water soluble

math
look at 100,000 people 800 have it ... 56 will show negative ... 744 will show positive 99200 don't have it ... 2976 will show positive probability of accurate positive ... 744 / (744 + 2976)

math
(2 * 27.5) + 30/2

Math - combinatorics/ permutations
looks good

Chemistry
molarity is moles solute per liter of solution 0.05144 moles / .38 L = ? significant figures?

science
a + b = 29 a - b = 5 2a = 34 ... a = 17 ... b = 12 (17 + 3)^2 + (12 + 3)^2 = r^2

Physics
m g h + 1/2 m v^2 = 1/2 m V^2 (2 * 9.8 * 65) + 12^2 = V^2

Mathematics.
ER , 1/5 off , 4/5 normal , 80% normal ... normal = 64 / .80 MW , 15% off , 85% normal normal = 64.60 / .85

Math
the sides and angles must be congruent if they are "regular" octagons, the side lengths must be equal

math
looks good

physics
m g h / t ... 75 * 10 * 12 * .20 / 5

Physics
on the side of the -9 away from the +16 let d = distance from -9 16 (d + 8)^2 = 9 d^2

Math
the nearest point, the end of the chord, and the end of a diameter (opposite the point) form a right triangle the half of the chord forms the altitude of the triangle 4 / 7 = 7 / (d - 4) solve for the diameter (which is twice the radius)

Science
the product of force and time is 3 3 N for 1 s isn't realistic for golf, but it's easy to work with f = m a ... 3 = .05 a ... a = 60 m/s^2 t = 1 s , so the velocity is 60 m/s

Precalculus -- Systems of Equations
thank you, bob we all try to bring enlightenment where we can

Precalculus -- Systems of Equations
x^2 + y^2 = r^2 is a circle of radius r, centered at the origin x - 2y = 8 is a line the question is asking what r must be for the line to be tangent to the circle the radius is perpendicular to the line at the point of tangency ... it is the shortest distance from the line to...

Geometry
the radius of the tank is 36" (3 ft) looking a the tank in cross section the width of the gasoline surface is the base of an isosceles triangle the height is ... 36 - 18 the sides are ... 36 use the vertex angle to find the area of the sector of the circle then find the ...

math
6/7 = 0.857142857142... 6 digits repeating 327/6 = 54 R3 ... 3rd digit of 6

Math
A = 1/2 * b * h

Math
3 congruent triangles make up the 3 sides the area of a side is ... 198 / 3 cm^2 the slant height is the height of a triangular side you have the area and the height of a triangle ... how do you find the base length?

Math (Physics)

Solid figures
? * (d/2)^2 * 42 = 30 * 231

sale price = list price - discount

science
refraction is the quality that causes the bending (focusing) of light rays it's what allows lenses to function

Science
sure ... post them and someone will check

Science
looks good

Science
a mole of O2 gives 2 moles of ZnO the molar mass of O2 is ... ? 2.25 g is ? moles of O2 the molar mass of ZnO is ... ?

Maths
741 / (9 + 105) = 6.5 ... so there are 13 terms (105 - 9) / (13 - 1) = 8 ... the common difference is 8

Physics
f = m v^2 / r f = 43 N * (59/15.89)^2 / (.948/2.1)

math
check the sign

math
tan(?) = 8/10

physics
2) 2 sec up and 2 sec down 1) ave vel = 10 m/s 10 m/s * 2 s = ?

Math (Physics)