Monday

February 27, 2017
Total # Posts: 1,848

**Geometry**

5 b + 5 b + b = 121

*January 24, 2017*

**Physics**

you're not accelerates to 12 m/s, then travels for 20 s ... that's 240 m, plus the acceleration distance d = 1/2 a t^2

*January 24, 2017*

**Geometric Progression.**

(x + 9) / x = (x + 22.5) / (x + 9) x^2 + 18 x + 81 = x^2 + 22.5 x 81 = 4.5 x a1, a2, 18, 27, 40.5

*January 24, 2017*

**Physics/Energy**

work = m g h the time is only a factor for power calculation

*January 24, 2017*

**Math**

60x + y = 87.15 subtracting equations ... 30x = 33.60 substituting ... 33.60 + y = 53.55 ... y = 19.95

*January 22, 2017*

**Matha**

compounding period?

*January 22, 2017*

**Physics**

KE = 1/2 m v^2 m = .02 kg v = (200000 / 3600) m/s answer is in Joules

*January 22, 2017*

**physics**

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

*January 22, 2017*

**Physics**

the same depth means the same pressure at the bottom the forces are equal

*January 22, 2017*

**science**

K.E. is proportional to the square of the velocity this means that the energy change from 80 kph to 70 kph is greater than the change from 10 kph to zero use (1/2 m v^2) to find the energies the lost energy (from braking) is usually frictional (heat)

*January 21, 2017*

**Maths**

each cut results in a cake that is 3/4 of the size before the cut starting with a whole cake (1) after 3 cuts ... 1 * (3/4) * (3/4) * (3/4)

*January 21, 2017*

**physics**

his energy at the bottom is the change in potential energy, minus the work of friction ... m * g * h - 520 * h ... E = (88 kg * 9.8 m/s^2 - 520 N) * 5.9 m his velocity is (from K.E. equation) ... v = ?(2 * E / m) while he is slowing down, his average velocity is ... (v + 0) / ...

*January 20, 2017*

**math**

2 x^2 + 13 x - 84 = 0 use the quadratic formula

*January 19, 2017*

**science**

the molar mass of sulfur is 32.1 g there are 6.02E23 atoms in a mole of sulfur (10.0 / 32.1) * 6.02E23

*January 19, 2017*

**Chemistry**

1. -3 means 3 "extra" electrons ... this element is atomic number 7 2. +2 means 2 "lost" electrons ... this element is atomic number 20 3. column 2, row 3

*January 18, 2017*

**math**

30 m / x = tan(78º)

*January 18, 2017*

**math**

[1 - (5/8)] * [1 - (1/6)]

*January 18, 2017*

**Geometry**

the x-distance from p1 to p2 is ... 6 - -4 the y-distance from p1 to p2 is ... 9 - -7 divide the distances by 4 to find the "length" of each step start at p1 and add consecutive steps to find the 3 division points

*January 18, 2017*

**algebra**

biologists use a Punnett square to show the geneotypes if both parents are RL, the following outcomes are equally probable ... RR, RL, LR, LL

*January 18, 2017*

**math**

2.1 = a [1/2^(1000/24360)] log(2.1) = log(a) + (1000/24360)log(1/2) 2.1606 ?

*January 18, 2017*

**MATH HELP**

the other 4 committee members come from the group of 6 faculty and 2 students ... 8C4 number of ways is ... 6P2 * 8C4

*January 18, 2017*

**Math**

a 5x5 grid has 25 blocks each block is 1/25 or 4% how many blocks for 24%

*January 18, 2017*

**Maths**

45 L is 45000 cm^3 (45000 / 2) seconds

*January 18, 2017*

**Pre-cal/trig**

the rope reaches around the corner on the 18 ft side, but not on the 22 ft side so the area is half of a 42 ft dia circle, plus a quarter of a 6 ft dia circle

*January 18, 2017*

**Math**

L = 3 T L + 15 + T + 15 = 38 substituting ... 3T + 15 + T + 15 = 38 = 4 T + 30 solve for T, then substitute back to find L

*January 18, 2017*

**Chemistry**

commercial ice cream is agitated more vigorously to aerate the mixture and increase the volume you pay for air that the manufacturer gets for free the product should probably be sold by weight, not volume

*January 17, 2017*

**Algebra**

Jacinda appears to be running 10 minute miles ... 6 mph after 1 hr, Raj has gone 6 mi ... that's when Jacinda catches him

*January 17, 2017*

**Physics**

momentum is conserved 4500 * 17.5 = v * (4500 + 1350)

*January 17, 2017*

**physics**

energy = m g h 3.9E5 = 1.3E3 * g * h

*January 17, 2017*

**physics**

friction force = centripetal force ? m g = m v^2 / r ? = v^2 / (g r)

*January 17, 2017*

**Physics**

the dimensions are given to 3 sig fig ... that's what the answer should have 1 m^3 = (3.28 ft)^3 v = 43 * 18 * 15 * 3.28^3 ft^3 ... use 3 significant figures in the answer

*January 17, 2017*

**serial dilutions**

the mix is 1.5 diluent to .5 solution each dilution results in a solution that is 1/4 the concentration of the added solution ... .5 mL / (.5 mL + 1.5 mL)

*January 17, 2017*

**Algebra 2**

?n = n^(1/2) ?(8 x^3 y^5)

*January 17, 2017*

**Algebra 2**

(7x-2)^1/4 = 5 7x - 2 = 625

*January 17, 2017*

**Math**

horizontal (x) component ... magnitude * cosine vertical (y) component ... magnitude * sine

*January 17, 2017*

**Algebra**

try this (.08 * x) + [.07 * (x - 1400)] = 217

*January 17, 2017*

**Physics**

h = 1/2 g t^2 ... ?(2h/g) = t the time is directly related to the square root of the height

*January 17, 2017*

**Physics**

cable exerts an upward force gravity exerts a downward force find the net force a = f / m

*January 17, 2017*

**Math**

the difference is -7 the 5th term is 10 differences before the 15th term

*January 16, 2017*

**physics**

average velocity during penetration is ... (500 + 0) / 2 time = distance / velocity

*January 16, 2017*

**science**

impulse is the change in momentum over time

*January 16, 2017*

**physics**

the force of the Earth on the ball is the same as the ball on the Earth f = m a use the drop time to find the velocity v = a t

*January 16, 2017*

**Math**

horizontal means zero slope set f' equal to zero and solve for x

*January 16, 2017*

**College Math - Quantitative Reasoning**

.93^3 = .804357 1 - .804357 = .195643 rounds to 19.6%

*January 16, 2017*

**College Math - Quantitative Reasoning**

what do you think is the right answer? the problem statement is not correct your calculations are fine

*January 16, 2017*

**Physics**

(a) looks good part (b) may be a "trick" question velocity is a vector quantity, while speed is a scalar the answer might be zero

*January 15, 2017*

**Chemistry**

sounds like hydrogen peroxide

*January 15, 2017*

**Math**

your work looks okay C1 is 60 times C2 ... so V1 should be 1/60 of V2

*January 15, 2017*

**Chemistry - Enthalpy**

the tea (water) loses the energy gained by the spoon 250.0 * (90.00 - 85.00) * 4.184 4 sig fig ... not 5 as in your answer

*January 14, 2017*

**Physics**

1/2 * 68.6 * (4.92^2 - 1.12^2)

*January 14, 2017*

**maths**

the whole circle is 2? ... or 20?/10 3?/10 - 20?/10 = ?

*January 13, 2017*

**math**

2L + 2W = 52 L = W + 4 substituting ... 2(W + 4) + 2W = 52 4W + 8 = 52

*January 13, 2017*

**algebra 2**

7C3 * 5C3

*January 12, 2017*

**algebra 2**

16000 is 4000 above the average 4000/3200 = 1.2 sd use a z-score table to find the probability

*January 12, 2017*

**Science**

an oxide ion will take on two electrons calcium has two valence electrons potassium has one valence electron

*January 12, 2017*

**Grade 6, percentage**

70% of (840 minus boys) ... equals ... 60% of 840 588 - .7b = 504 84 = .7b

*January 12, 2017*

**algebra**

s + p = 330/11 = 30 s - p = 330/15 = 22 adding eqns ... 2s = 52

*January 12, 2017*

**Math**

correction ... 5/2 m = 2.25

*January 12, 2017*

**Math**

3b + 2m = 7 2b + 5m = 6.50 solve the system by substitution or elimination 2nd eqn times 3/2...3b + 15/2 m = 9.75 subtracting (to eliminate b) ... 5/2 m = 3.25

*January 12, 2017*

**PLEASE HELP BEEN STUCK ALL DAY CALCULUS**

nominal ... ? * 4^2 * 12 max ... ? * 4.2^2 * 12 min ... ? * 3.8^2 * 12 units are in^3

*January 11, 2017*

**physics**

a = f / m = (16890 - 1010) / 1450

*January 11, 2017*

**Algebra 2**

the factor is ... [1 + (% change)]^(years) 1 + .70 1 - .75

*January 11, 2017*

**Algebra**

the variable is to the 1st power so, yes

*January 11, 2017*

**algebra**

.....4b^2 + 2b + 1 ....._____________________ 2b-1 [8b^3 + 0b^2 + 0b - 6 ......8b^3 - 4b^2 .............4b^2 + 0b .............4b^2 - 2b ....................2b - 6 ....................2b - 1 .........................5 remainder

*January 11, 2017*

**Science**

maybe look at B?

*January 9, 2017*

**Trig**

cos = ?(1 - sin^2) 0 + ?/2 < x + y < ?/2 + ? ... ?/2 < x + y < 3?/2 the sign of the solution will be neg

*January 4, 2017*

**Algebra 2**

each year, the number of trucks is 110% of the previous year T(r) = 100 * (1 + .10)^r

*January 4, 2017*

**Science**

distance = 1/2 a t^2 871 = 25 a gravitational force must be overcome f - g = m a = 5 a f = 5 a + g

*January 4, 2017*

**Physics**

d = 1/2 a t^2 10.0 * 2 = a * 2.65^2 calculate the gravitational acceleration (a) ... f = m a ... f / m = a f = M * m * G / r^2 ... f / m = M * G / r^2 ... a = M * G / r^2 M is the planet's mass G is the universal gravitation constant r is the planets radius (in meters)

*January 3, 2017*

**Physics**

100 kg/s energy (work) = m * g * h ... = 100 kg * 9.8 m/s^2 * 100 m ... = Joules energy / time = power ... Joule / s = watt

*January 2, 2017*

**Spanish**

hola ipap da loemlo

*December 18, 2016*

**Math Homework**

looks good

*December 17, 2016*

**Math**

.03 j = .05 s j = s + 500

*December 9, 2016*

**Math**

Will you marr... me

*December 9, 2016*

**Math**

x + y = 24 y + 12 = z x + y + 12 = 36 x + z = 36 (x + z) / 2 = 18

*December 9, 2016*

**Physics**

w = f * d Newtons * Meters = Joules

*December 8, 2016*

**Algebra**

18 - 7 17 - 8 16 - 9 15 - 1 14 - 2 13 - 3 12 - 4 11 - 5 10 - 6

*December 8, 2016*

**Physics**

radius is half the diameter

*December 8, 2016*

**Algebra**

m = (y2 - y1) / (x2 - x1) if x and y change in the SAME direction (up or down), then the slope is positive if they change in opposite directions, the slope is negative -5/-3 is not the same as -5/3 ... one is positive, the other negative

*December 8, 2016*

**math**

60 seconds in a minute

*December 8, 2016*

**physics**

w = f * d (Joules, in this case)

*December 8, 2016*

**Probability Help**

there are [(40 * 39) / 2] separate pairs of people the probability of two people not having the same birthday is (364 / 365) the probability that none of the group have the same birthday is ... (364 / 365)^(20 * 39)

*December 8, 2016*

**Algebra**

s + a = 350 1s + 3a = 450 elimination looks pretty good

*December 7, 2016*

**Physic**

constant velocity - no acceleration net force is zero friction and push cancel each other

*December 7, 2016*

**Physics**

figure???

*December 7, 2016*

**math**

point-slope Y - y1 = m (X - x1)

*December 7, 2016*

**Geom A**

6. try again the sides are in the same size order as their opposite angles <C is the largest, so AB is the largest side 7. try again any one side must be LESS THAN the sum of the other two sides

*December 7, 2016*

**Algebra**

There is no twins age given, sorry, this is the full question

*December 7, 2016*

**Algebra**

I am 6 years older than my wife. Our twins go to the local comprehensive school. One of the twins noticed that the sum of their ages divided into the product of my age and the age of my wife is 63. How old am I?

*December 7, 2016*

**math**

looks good

*December 6, 2016*

**Calculus applications**

The bending moment (M) along a beam is M = WLx/2 -Wx2/2 kNm where x is the distance of a beam length L from the left hand end. W is the weight per unit length. (a) Shear force is calculated as the differential of bending moment. Find an expression for shear force and determine...

*December 5, 2016*

**Math**

how can the perimeter be less than the diagonal? you found one of the sides...the perimeter is all four

*December 4, 2016*

**Algebra**

d + n = 28 10d + 5n = 195 solve the system ... substitution or elimination

*December 4, 2016*

**math algebra**

you have everything you need just crank the crank

*December 4, 2016*

**math**

2 = [1 + (p / 100)]^2 ?2 = 1 + (p / 100)

*December 4, 2016*

**Maths**

try nesting polygons ... going from the outside in connecting adjacent points gives 64 sides (chords) every other point gives 32 sides every 3rd point. etc...

*December 3, 2016*

**Physics**

a) looks good b) you know the kinetic energy at the top ... just add the gravitaional potential (mgh) across the loop to find the bottom speed

*December 3, 2016*

**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*