Friday

May 6, 2016
Total # Posts: 2,409

**statistics**

When drawing a histogram, it is important to a. eliminate the extremes to minimize the effect of skewness. b. choose class intervals, so they all have the same number of observations c. make sure that the mean and the median fall in the same class interval, so that the correct...
*February 20, 2015*

**math**

a recipe calls for 2/3 cup of flour i am making a amount that is 3/7 of the recipe how much flour do i need
*February 19, 2015*

**Science**

I got 100% thx
*February 19, 2015*

**alg 1**

the perimeter of a rectangle is 24 m. the width is 30 m less than five times the length. find the dimentions of the rectangle.
*February 13, 2015*

**chemistry**

how many grams of calcium bicarbonate would it take to reach a ph of 7 if i have 10ml 3 molar sulfuric acid?
*February 10, 2015*

**Math**

After a busy day of orders, a florist has 6 roses, 7 lilies, 3 carnations, 35 chrysanthemums, 27 sunflowers, 18 violets, and 9 tulips left in her inventory. Part A: Write a ratio that compares the number of roses to the number of violets. Part B: Describe what three other ...
*February 9, 2015*

**math**

An object is thrown vertically so that its height in feet above the ground x seconds after it is thrown can be found using the following quadratic function f(x)=-16x^2+64x+80
*February 9, 2015*

**MATH**

Assuming the interest is compounded annually. You are finding the interest 21 times. There is a formula for it that you can certainly Google or you can just simply take the amount 300*(1.055)=SUM and do the same to the sum each time SUM*(1.055). I believe its answer is 923.47...
*February 7, 2015*

**Chem/Hydrocarbons**

So for methane through decane determining and drawing the isomers should be straight forward? Im just unsure as how to determine what makes them unique and if the structure and such matter in terms of location. If that makes any sense haha...Thanks for responding by the way
*February 7, 2015*

**Chem/Hydrocarbons**

Determining and naming the unique isomers of a hydrocarbon? Please help!? Hey all. I am studying a petroleum fluids class and am having difficulty in understanding one topic. Specifically, in some cases we are asked to draw and name the unique isomers of a certain compound. ...
*February 7, 2015*

**physics**

A space satellite has a total mass of 500kg. A portion of mass 20kg is ejected a velocity of 10ms-1 . Calculate the recoil velocity of the remaining portion (ignoring the initial velocity of the satellite).
*February 2, 2015*

**Chem**

a solution is prepared by dissolving 0.47 g of a solute in 12.7 g of cyclohexane what is the freezing point change
*February 1, 2015*

**Chem**

a solution is prepared by dissolving 0.47 g of a solute in 12.7 g of cyclohexane what is the freezing point change
*February 1, 2015*

**Chem**

a solution is prepared by dissolving 0.47 g of a solute in 12.7 g of cyclohexane what is the boiling point
*February 1, 2015*

**10th algebra**

x2+22x +c find the value of c that makes the trinomial a perfect square
*January 28, 2015*

**math**

Emma is using connecting cubes to make a rectangular model with a height of one connecting cube. With her cubes she can make the model in exactly 3 different ways. If Emma has more than 12 but fewer than 17 cubes, how many cubes does she have?
*January 23, 2015*

**physics**

HENRY, it's a good job.
*January 23, 2015*

**physics**

A copper telephone wire has essentially no sag between poles 30 m apart on a winter day when the temperature is −16◦C. How much longer is the wire on a summer day when the temperature is 26 ◦C? Assume that the thermal coefficient of copper is constant ...
*January 22, 2015*

**Mathematics arithmetic sequence**

I really don't understand this sequence... help plz
*January 18, 2015*

**5th grade math**

Julian wants to put a border around two sides of his rectangular shaped garden. he has a 12 foot piece of lumber that will be cut into 1/3 foot pieces. how many 1/3 foot pieces can Julian cut from the lumber? 12 divided by 1/3
*January 13, 2015*

**statistics**

Statistics students were asked to go home and fill a 1-cup measure with raisin bran and to tap the cup gently on the counter 3 times to settle the contents. Then, if necessary, add more raisin bran to bring the contents exactly up to the 1-cup line. Once at the 1-cup line, the...
*January 13, 2015*

**Language arts**

Ms. Sue i never thought that i would hear such language from anyone on jiskha, much less you!
*January 7, 2015*

**Science**

C B B D Got a 100%
*January 6, 2015*

**mathematics**

If there are 18 elements in a set how many possible subsets of 6 can I get
*January 3, 2015*

**math**

How many subset of 6 can I get from 18 elements
*January 1, 2015*

**Lotto**

Next winning
*December 22, 2014*

**math**

A punch recipe calls for two-thirds of a cup of fruit juice for each pint of soda the ratio of soda to fruit juice in the punch is what?
*December 18, 2014*

**Physics**

An attack helicopter is equipped with a 20 mm cannon that fires 116 g shells in the forward direction with a muzzle speed of 819 m/s. The fully loaded helicopter has a mass of 4870 kg. A burst of 96.2 shells is fired in a 4.51 s interval. What is the resulting average force on...
*December 17, 2014*

**Calculus**

If the y-coordinate at each point of inflection on the curve y=e^(-x^2) is 1/e^a, then a = ?
*December 10, 2014*

**Physics**

An 11 kg object moves down a 25 degree incline at a constant speed. what is the magnitude of the coefficient of friction? I have m=11.0kg incline = 25 deg but i feel like I am missing one more number in order to calculate
*December 10, 2014*

**Math**

A taxi charges $1.00 for the first mile and $.20 for an additional 1/6 of a mile. How far can you travel for $5.00.
*December 4, 2014*

**physics **

If the acceleration due to gravity on the earth is 9.8 m/s2, what is the acceleration due to gravity on Rams?
*December 4, 2014*

**Thermodynamics**

Drawing a blank studying last minute for an exam: when does a piston cylinder not follow the 2nd law of thermodynamics!!!!
*November 25, 2014*

**pt1420 **

if the expression is false, the_____ operator will return true.
*November 24, 2014*

**Chemistry 211**

Which of the following statements is a reasonable explanation for why a percent yield may be less than 100% for the synthesis of the alum, select all that apply. a) The aluminium foil did not completely react b) Some alum sample remained in the beaker and was not transferred ...
*November 24, 2014*

**Physics**

A lathe, initially at rest, accelerates at .60 rad/s^2 for 10s, then runs at a constant angular velocity for 20s, and finally decelerates uniformly for 10s to come to a complete stop. What is its average angular velocity?
*November 23, 2014*

**Physics**

A boy wants to throw a ball into his friend’s window 16.0 m above. Assuming it just reaches the window, he throws the ball at 55.0° to the ground. At what velocity should he throw the ball?
*November 23, 2014*

**Physics**

A lathe, initially at rest, accelerates at .60 rad/s^2 for 10s, then runs at a constant angular velocity for 20s, and finally decelerates uniformly for 10s to come to a complete stop. What is its average angular velocity?
*November 23, 2014*

**math**

so i thick it is 6
*November 20, 2014*

**4th grade Math**

What is an expression that can be used to find 4 x 275 using mental math and properties of numbers?
*November 18, 2014*

**Physics**

The pistons of a hydraulic press have radii of 2.00cm and 12.00cm, respectively. A) What force must be applied to the smaller piston to exert a force of 5250N on the larger piston? B) What is the pressure in (N/cm2) on each piston? C) What is the mechanical advantage of the ...
*November 16, 2014*

**Calculus**

I got this equation from some girl that is on an online dating service. She says she wants to date someone who knows what those numbers mean, and she's hot....I'll give you the web info if you want it, just for fun of course.
*November 10, 2014*

**Calculus**

What does this equation mean? X = Cos (T) * Phi ^ ((2 / Pi) * T) Y = Sin (T) * P
*November 10, 2014*

**Physics**

A space vehicle is orbiting Earth in a circular orbit with a radius of 10,300,000m. What is the minimum increase in speed that is needed for the vehicle to escape Earth's gravitational field? The mass of the Earth is 5.97x10^24 kg and G = 6.67x10^-11 N*m^2/kg^2. The answer...
*November 10, 2014*

**Physics**

A mass of 100g is attached to one end of a massless rod, 10cm in length, which is pivoted about the opposite end. The rod is held vertical, with the mass at the top, and released. The rod swings. A. What is the speed of the mass at the instant that the rod is horizontal? B. ...
*November 10, 2014*

**Math**

What is the probability that a randomly thrown dart hits a shaded region, given that the dart lands within the rectangle? All of the circles are congruent, and the diameter of each circle is 6 cm.
*November 6, 2014*

**Physics**

An object of mass 1.00 kg is attached to a vertical spring with spring constant 100 N/m. The object is held at rest in a position such that the spring is stretched upward a distance 1.00 cm beyond its undisturbed length. If the object is released, how far will it drop before ...
*November 5, 2014*

**Math**

What is the multiplier for 3/8 and 6/8
*November 4, 2014*

**algebra**

In a change jar, Tom has nickels and dimes. The number of nickels is two times the number of dimes and the total amount of money in the jar is $1.20. How many dimes are in the jar?
*November 4, 2014*

**chemistry**

50 mL of water at 48.9EC were mixed with 50 mL of water at 23.8EC in a calorimeter also at 23.8EC. The final temperature was 33.1EC. Assuming that neither the density of water nor its specific heat capacity change with temperature, calculate the total heat capacity of the ...
*November 3, 2014*

**physics**

A ball is rolled up a ramp at 2.50 m/s. The ball slows down for 5.00 s and then rolls back down. Assume frictions isn't a factor and that the up ramp is the positive. At what point does the ball's acceleration change and what is the acceleration on the way down?
*October 30, 2014*

**Math**

Use the distributive property to rewrite the expression 1/2(C-8)=
*October 27, 2014*

**Math**

Find a fraction between 7/9 & 8/9
*October 23, 2014*

**Math**

Please check 2/5 + (-7/8) = -6
*October 15, 2014*

**Math **

Please check 15/16 x 2/3 = 5/8
*October 15, 2014*

**Linear Algebra**

Find the eigenvalues and corresponding eigenvectors of the matrix: 0 0 1 M = 1 0 0 0 1 0
*October 13, 2014*

**Math**

If I plan to average 80 kilometers per hour and stop 45 minutes for lunch how long will it take me to make a 220 kilometer trip?
*October 9, 2014*

**Math**

(5.63+.918) - (.83+.9) = 6.548 - .173 = 6.375
*October 9, 2014*

**Math**

How do rate tables help me find equivalent ratios
*October 9, 2014*

**Chemistry**

The oxidation of iodide ion by arsenic acid, H3AsO4, is described by the balanced equation 3I−(aq)+H3AsO4(aq)+2H+(aq)→ I3−(aq)+H3AsO3(aq)+H2O(l) If −Δ[I−]/Δt = 4.8×10−4M/s , what is the value of Δ[I3−]/Δt ...
*October 5, 2014*

**Chemistry**

The oxidation of iodide ion by arsenic acid, H3AsO4, is described by the balanced equation 3I−(aq)+H3AsO4(aq)+2H+(aq)→ I3−(aq)+H3AsO3(aq)+H2O(l) If −Δ[I−]/Δt = 4.8×10−4M/s , what is the value of Δ[I3−]/Δt ...
*October 5, 2014*

**statistics**

In a major city 7 % of cars have an alarm system installed. A car without an alarm has a probability of 0.01 of being stolen, this is triple the probability of a car with an alarm being stolen. What is the probability that a car stolen from this city has an alarm system ...
*October 4, 2014*

**math **

Michael's father broughthim a 16-foot board to cut into 11 equal sizes lengths for his shelves The saw blade that Michael will use to cut the board will change the length of the board by -0.125 inches for each cut. How will this affect the total length of the board?
*October 3, 2014*

**business**

Do not go by the above answer. All you need to know is : what is given up (18 shirts) divided by what is gained 3 icecreams for the first one. The second is the same principle given up/gained.
*September 25, 2014*

**Physics**

6.5 ft
*September 21, 2014*

**math**

5 1/2
*September 21, 2014*

**Math**

Place parentheses to make this statement true: 6-6/6x6+6=0
*September 21, 2014*

**Chemistry**

wow thats really easy, thank you
*September 21, 2014*

**Chemistry**

What osmotic pressure in atmospheres would you expect for a solution of 0.150M CaCl2 that is separated from pure water by a semipermeable membrane at 310 K? Assume 100% dissociation for CaCl2 Any help is appreciated, thank you!
*September 21, 2014*

**Chemistry**

Thanks, I figured this one out, can you help me on the other one?
*September 21, 2014*

**Chemistry**

What partial pressure of oxygen above the water (in atmospheres at 0 C ) is needed to obtain this concentration? The solubility of O2 in water at 0 C and 1 atm partial pressure is . 2.21 x 10^-3 mol/L Concentration needed is 4mg/L Stuck and need help, anything is appreciated!
*September 21, 2014*

**chemistry**

What is the density of a piece of zinc that has a volume of 8000 cubic cm? density= mass/ volume
*September 21, 2014*

**Algebra( check my answers)**

i know because i am in k-12
*September 19, 2014*

**Algebra( check my answers)**

number one is A:12
*September 19, 2014*

**Chemistry**

If the edge length of an NaH unit cell is 488pm, what is the length (in picometers) of an Na−H bond? Na−H has face-centered cubic unit cell. Please help
*September 14, 2014*

**Chemistry**

An element crystallizes in a body-centered cubic lattice. The edge of the unit cell is 3.13Å , and the density of the crystal is 7.78g/cm3. Calculate the atomic weight of the element. Please help, thanks
*September 14, 2014*

**physics**

A certain circuit breaker trips when the rms current is 50.0 A. What is the corresponding peak current?
*September 13, 2014*

**physics**

A North American tourist takes his 22.0–W, 120–V AC razor to Europe, finds a special adapter, and plugs it into 240 V AC. Assuming constant resistance, what power does the razor consume as it is ruined?
*September 13, 2014*

**physics**

P = I²R = 1*2.5 = 2.5 watts 1 watt is a Joule per second, or a Joule is a watt-second E = 2.5 J/s x 4.0s = 10 Joules It says I need more numbers for the answer...
*September 13, 2014*

**physics**

A current of 1 A is maintained in a simple circuit with a total resistance of 2.5 Ω. How much heat is generated in 4.0 s?
*September 13, 2014*

**physics**

A light–rail commuter train draws 645 A of 590–V DC electricity when accelerating. What is its power consumption rate in kilowatts? How long does it take to reach 30.0 m/s starting from rest if its loaded mass is 4.50×104 kg, assuming 91.0% efficiency and ...
*September 13, 2014*

**physics**

I got the first part of the question right. It was 32.2 W How would I do the second part?
*September 13, 2014*

**physics**

A cauterizer, used to stop bleeding in surgery, puts out 2.30 mA at 14.0 kV. What is its power output? What is the resistance of the path?
*September 13, 2014*

**Physics**

With a 1220–W toaster, how much electrical energy is needed to make a slice of toast (cooking time = 1.3 minute)? At 12.1 cents/kW·h, how much does this cost? (You do not need to enter any units.)
*September 13, 2014*

**10**

A runner is at the starting gate and hears the starting gun. He begins running with a constant acceleration ai = 0.55 m/s2. He crosses the finish line at d = 100 m and then begins slowing down. It takes him tr to cross the finish line. It takes him ts = 6.5 s to return to rest...
*September 11, 2014*

**10**

A runner is at the starting gate and hears the starting gun. He begins running with a constant acceleration ai = 0.55 m/s2. He crosses the finish line at d = 100 m and then begins slowing down. It takes him tr to cross the finish line. It takes him ts = 6.5 s to return to rest...
*September 11, 2014*

**6**

A student begins at rest and then walks north with an average speed of v1 = 0.85 m/s. The student then turns south and walks with an average speed v2 = 0.45 m/s. (a) What was the student's overall average velocity vavg, x, in m/s, for the trip assuming the student spent ...
*September 11, 2014*

**3**

t= 5.79 (a) There are approximately 1609 meters per mile. If the sun is 93 million miles away, how far is the sun in kilometers to two significant figures.
*September 11, 2014*

**3**

An astronomy student is studying the sun. While monitoring her equipment, she observes a solar flare. She then observes the reflection of the solar flare off of a passing satellite and with her equipment she is able to determine that the reflected light arrives from the ...
*September 11, 2014*

**2**

Assume that an intercontinental ballistic missile goes from rest to a suborbital speed of 6.50 km/s in 60.0 s (the actual speed and time are classified). What is its average acceleration in m/s2 and in multiples of g (9.80 m/s2)?
*September 11, 2014*

**2**

A student witnesses a flash of lightning and then t = 6.5 s later the student hears the associated clap of thunder. Light travels at 3.0 × 108 m/s in the air. How long, t1, in seconds did it take the light to reach the student's eyes after the flash?
*September 11, 2014*

**physics**

A student witnesses a flash of lightning and then t = 6.5 s later the student hears the associated clap of thunder. Light travels at 3.0 × 108 m/s in the air. How long, t1, in seconds did it take the light to reach the student's eyes after the flash?
*September 11, 2014*

**1**

A student witnesses a flash of lightning and then t = 6.5 s later the student hears the associated clap of thunder. Sound travels at 343 m/s in the air. What distance from the student is the lightning strike, in meters?
*September 11, 2014*

**physics**

Assume that an intercontinental ballistic missile goes from rest to a suborbital speed of 6.50 km/s in 60.0 s (the actual speed and time are classified). What is its average acceleration in m/s2 and in multiples of g (9.80 m/s2 )?
*September 11, 2014*

**physics**

A commuter backs her car out of her garage with an acceleration of 1.40 m/s2. (a) How long does it take her to reach a speed of 2.00 m/s? (b) If she then brakes to a stop in 0.800 s, what is her deceleration?
*September 11, 2014*

**Chemistry**

NaHCO3 + HCl = NaCl + H2O + CO2 The there are .0489 moles of CO2, and HCL is 6M. find the amount of HCL in mL and the grams of NaHCO3
*September 7, 2014*

**physics**

Clint Dempsey takes a free kick and kicks a soccer ball with a mass of 440 grams at 98 miles per hour. what is the momentum
*September 7, 2014*

**Physics-Electricity**

Consider three charged particles placed along the x-axis. The particle with q1 = 9.30 nC is at x = 6.87 m and q2 = 4.09 nC is at x = 0.600 m. Where must a positive charge, q3, be placed such that the resultant force on it is zero? x=?m
*August 31, 2014*

**physics**

Vector has a magnitude of 136 units and points 35.0 ° north of west. Vector points 69.0 ° east of north. Vector points 19.0 ° west of south. These three vectors add to give a resultant vector that is zero. Using components, find the magnitudes of (a) vector and (b...
*August 26, 2014*