# Posts by David

Total # Posts: 2,252

**Math**

3/11 eleven up on three.

*January 17, 2016*

**chemistry**

1 gm of magnesium is burnt in a closed container which contains 2 l of air at ntp containing 21 percent oxygen by volume find limiting reagent, mass of excess reagent left over, mass of mgo produced, number of mg and oh ion formed by dissolving it with water

*January 14, 2016*

**Math**

Thank you so much Reiny! I finally understand it!

*January 13, 2016*

**Math**

(2+3i)^6 Using Demoirves Theorem. I tried solving it out, but somehow it didn't work for me. (2+3i)^6 r=|z|=square root of 2^2 + 3^2 = square root of 13 z = square root of 13 * (cos____ + isin_______ ) At this point I am stuck, so can someone help me?

*January 13, 2016*

**physicss**

Pls be mathematical

*January 10, 2016*

**physicss**

Two point charges experience an attractive force of 5N when they are separated by 1m.what force do they experience when their separation is 2m? What is the value of the charges Using coluomb's law F=KQ1Q2/r^2 5=8.99*10^9*Q1*Q2/1

*January 10, 2016*

**university**

As=total distance covered/time taken

*January 10, 2016*

**Physics**

A long thin rod lies along the x-axis from the origin to x=L, with L= 0.750 m. The mass per unit length, λ (in kg/m) varies according to the equation λ = λ0 (1+1.410x3). The value of λ0 is 0.600 kg/m and x is in meters. 1) Calculate the total mass of the ...

*January 9, 2016*

**Science**

Ice at 0 degree celcuis is added to 200g of water initially at 70 degree celcuis in a vacuum flask.When 50g of ice has been added and has all melted the temperature of the flask and contents is 40 degree celcuis.When a further 80g of ice has been added and has all melted the ...

*January 8, 2016*

**Math**

Wrong, the answer is C.

*January 5, 2016*

**Math**

answer is A

*January 5, 2016*

**Math**

2x+1=4x-5 2x=6 x=3 y=2x+1 7=2(3)+1 7=7 The answer would be D.

*January 5, 2016*

**MATH help ty**

2x+1=4x-5 2x=6 x=3 y=2x+1 7=2(3)+1 7=7 The answer would be D.

*January 5, 2016*

**Math (Help) thx!**

D. No Solution Through the use of elimination the positive and negative 7x would cancel each other out and the positive and negative 15y would also cancel out. You are then left with 0 value so there would be no solution.

*January 5, 2016*

**Trigonomentry help plz thanks**

Really, that is inappropriate. I am sorry Collins that I can't help you with this question. I am currently in Pre-Calc so I haven't learned this topic in great detail yet.

*January 4, 2016*

**science**

Thank you!

*January 4, 2016*

**science**

I am wondering why H2S has only London Dispersion forces and not Hydrogen Bonding?

*January 4, 2016*

**grammar**

The sentence structure seems to be a bit weird. The part "also fattens" makes no sense and it doesn't seem like it would belong in this particular sentence. Could you rephrase it? Is this a homework problem?

*January 4, 2016*

**grammar**

Is that another question or is it a statement?

*January 4, 2016*

**grammar**

I think the correct option would be number 4. "Finishing quickly is not as important as answering all question correctly". Using this word in the sentence would make the most sense. I also recognized an error: the word question should be plural. So, "Finishing ...

*January 4, 2016*

**chemistry**

I am wondering why H2S has only London Dispersion forces and not Hydrogen Bonding?

*January 4, 2016*

**Math -Algebra**

Is it one unit down or 5 units down?

*January 4, 2016*

**math**

Thank you so much! I get it now!!!

*January 4, 2016*

**math**

Evaluate tan (inverse cosine of 2/3). a. square root of 5 divided by 2 b. square root of 5 divided by 3 c. square root of 5 divided by 5 I have a feeling that the answer would be a but what i am confused about is how do we figure out what the value is for inverse cosine of 2/3.

*January 4, 2016*

**Math**

Solve the system using substitution: x = y - 6 y = 6 - 3x Answer choices: (0,6) (6,0) (0,-6) (-6,0) (

*January 3, 2016*

**Math**

How many triangles exist when the measure of angle B is 100 degrees, a =10 and b=5? a. none b. 1 triangle c. 2 triangles I have already solved this and I have found that there will be no triangle because by using the law of sines I found that the value is bigger than 1. So, I ...

*December 27, 2015*

**sri sri ravishankar**

What is the ratio of cups of cereal to cups of chocolate chips? What type of ratio is this?

*December 18, 2015*

**Math Help!**

The radius of this circle is one unit. Find the exact lengths of the legs in the right triangle if: Sides a is twice as long as side b. And Sides b is twice as long as side a. Basically the hypotenuse of this triangle is 1 and we are trying to use the pythagorean theorem to ...

*December 12, 2015*

**algedra**

y=6x+5 and y=6x-7 These to lines are parallel because they have the same slope. y=6 and y=-8 doesn't even have a slope so they are not related. If it was y=6x+5 and y=-1/6x-7, then the two equations would be perpendicular because they are opposite reciprocals.

*December 12, 2015*

**chemistry**

I forgot to tell you that this answer is true. Trust me, I'm in AP chemistry right now.

*December 12, 2015*

**chemistry**

this is simple. do 12.04 * 10^23 molecules of oxygen multiplied by 1 mole divided by 6.02 * 10^23 molecules of oxygen 12.04 * 10^23 molec. of Oxygen * (1 mol / 6.02 * 10^23 molec. ) = 2 moles of oxygen

*December 12, 2015*

**Math Help Please**

The radius of this circle is one unit. Find the exact lengths of the legs in the right triangle if: Sides a is twice as long as side b. And Sides b is twice as long as side a. Basically the hypotenuse of this triangle is 1 and we are trying to use the pythagorean theorem to ...

*December 12, 2015*

**Math Help**

you can make a right triangle with the radius. Basically the hypotenuse of this triangle is 1 and we are trying to use the pythagorean theorem to find the lengths of side a and b according to the terms described above.

*December 12, 2015*

**Math Help**

The radius of this circle is one unit. Find the exact lengths of the legs in the right triangle if: Sides a is twice as long as side b. And Sides b is twice as long as side a.

*December 12, 2015*

**Math**

The radius of this circle is one unit. Find the exact lengths of the legs in the right triangle if: Sides a is twice as long as side b. And Sides b is twice as long as side a.

*December 12, 2015*

**Math**

Michael has $50 to spend at the fair .the admission is $10 and each ride is $3.00 ,write an inequality that expresses the number of rides that Michael can ride

*December 12, 2015*

**Math**

Diego's deposit $100 and saves $10 per month .write an equation that represent the total amount in his account for x months

*December 12, 2015*

**PHYSICS**

I get V'2 = 1.09 m/s and V'1 = 1.99 m/s Does anyone else concur?

*December 11, 2015*

**PHYSICS**

A marble with a mass of 0.5 kg is moving to the right at 1.25 m/s and a second marble with a mass of 0.35 kg is moving to the left at 2.15 m/s. If they collide head on and the collision is elastic find the final velocities of the two marbles

*December 11, 2015*

**pharmacy procedures**

how many grams of hydrocortisone are present in 40g of a 2.5 percent hydrocortisone ointment

*December 10, 2015*

**Opinion Question**

Give me some ideas please. How technology reveals something deeper and essential about human nature: either our strengths or limitations, or both.

*December 4, 2015*

**math**

What will be the height of the house if the tower and the house are 50m apart.

*November 24, 2015*

**Genetics/Bio**

D, B

*November 18, 2015*

**chem**

How many grams of Na2SO4 are present in 500. mL of a 0.750 M aqueous solution? a.70.9 g b.53.3 g c.0.284 g d.106 g e.2.63 g A serum concentration of Mg2+ of 1.75 mmol/L is equivalent to: a.3.50 mEq/L b.1.75 mEq/L c.17.5 mEq/L d.0.875 mEq/L

*November 17, 2015*

**chem**

7.76 g of KBr was dissolved in water. The solution was diluted to a volume of exactly 250 mL. What is the molarity of the solution? 32.2 M a.0.476 M b.0.0652 M c.0.0310 M d.0.261 M

*November 17, 2015*

**chem**

A solution is prepared by adding 25.0 g of methanol to water to make a total volume of solution of 95.4 mL. What is the weight/volume percent of this solution? a.26.2% b.3.81% c.20.8% d.25.0%

*November 17, 2015*

**chem**

At STP a sample of methane gas occupies a volume of 1250 mL. What is the volume of the methane at 100.°C and 760. torr? a.1710 mL b.1250 mL c.915 mL d.1420 mL

*November 17, 2015*

**chem**

I am filing out a study guide and needed coaching on some question. thank you 0.765 g of He is placed in a balloon at 1.15 atm. The balloon expands to volume of 5.00 L. What is the temperature of the balloon? a,3.45 K b,91.6 K c,93.4 K d,366 K

*November 17, 2015*

**Calc**

A manufacture has been selling 1150 television sets a week at $510 each. A market survey indicates that for each $13 rebate offered to a buyer, the number of sets sold will increase by 130 per week. a) Find the function representing the demand p(x), where x is the number of ...

*November 16, 2015*

**Calc**

An open box is to be made out of a 10-inch by 16-inch piece of cardboard by cutting out squares of equal size from the four corners and bending up the sides. Find the dimensions of the resulting box that has the largest volume. Dimensions of the bottom of the box:

*November 16, 2015*

**Calc**

Thank you

*November 16, 2015*

**Calc**

A stone dropped into a still pond sends out a circular ripple whose radius increases at a constant rate of 2.6 ft/s. (a) How rapidly is the area enclosed by the ripple increasing when the radius is 4 feet? The area is increasing at

*November 16, 2015*

**Math**

The top and bottom margins of a poster are 6 cm and the side margins are each 7 cm. If the area of printed material on the poster is fixed at 384 square centimeters, find the dimensions of the poster with the smallest area.

*November 16, 2015*

**Math**

A set costs half as much as a book.A book costs 600$ more than a pen.If the total cost of the three items is 6900$,find the cost of a set.

*November 16, 2015*

**maths**

there were 32 boys and 13 girls in a school football team they wanted to play 5 a-side football how many teams can they make?

*November 11, 2015*

**Physics**

I am not about to get Vyellow or Vred by itself to solve

*November 10, 2015*

**Physics**

Two cars collide as shown in the figure. The yellow car is initially heading east and has a mass of 1000 kg. The red truck is initially heading north and has a mass of 2000 kg. The two vehicles collide, stick together, and veer off at a velocity of 16 m/s at a direction of 24 ...

*November 10, 2015*

**Physics**

Thank you so much

*November 10, 2015*

**Physics**

A sprinter accelerates at the start of the race at 8.5 m/s^2. After 1.3 seconds the sprinter runs the rest of the 100m race at a constant velocity. What was the sprinter's time at the finish line?

*November 3, 2015*

**Biology Answer Check**

In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent of offspring that will be tall if a heter In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent...

*October 25, 2015*

**answer check**

In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent of offspring that will be tall if a heter In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent...

*October 25, 2015*

**microbiology**

In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent of offspring that will be tall if a heter In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent...

*October 25, 2015*

**geometry**

How can I turn 192cubic cm into a triangular prism?

*October 25, 2015*

**Math**

A rock is thrown upward from a bridge that is 88 feet above a road. The rock reaches its maximum height above the road 0.67 seconds after it is thrown and contacts the road 3.18 seconds after it was thrown. Define a quadratic function, f, that gives the height of the rock ...

*October 23, 2015*

**MaTH**

5+r/14 3x-4=23 4

*October 23, 2015*

**HELP AZAP**

-5*x=-35 divide both sides by -5 x=7

*October 23, 2015*

**Science**

ANON IS RIGHT 7/7 100%

*October 21, 2015*

**History**

Does anyone know what impact has gothic architecture had on modern architecture?

*October 17, 2015*

**Physics**

In a glancing collision between two identical steel spheres, which of the following statements are correct? (Assume this collision is perfectly elastic. Select all that apply.) a) The velocities of the spheres after the collision in the direction perpendicular to the incoming ...

*October 15, 2015*

**Physics**

A steel ball rolls off a flat table of height 1.05 m with a velocity of 1.90 m/s a) How long will it take the ball after leaving contact with the table to hit the ground? b) How far from the edge of the table will the ball hit the floor?

*October 15, 2015*

**History**

Need help with study guide!! 1. What are two inventions/concepts that Eli Whitney is known for? 2. Why did New England become the center of the American Industrial Revolution? 3. What was a key element in developing a market economy in nineteenth century America? 4. What was ...

*October 15, 2015*

**Math**

Building A is 190 feet shorter than Building B. The total height of the two buildings is 1520 feet. Find the height of each building.

*October 14, 2015*

**Math**

well you will have 20 dimes and 16 quarters.

*October 13, 2015*

**Math**

Consider the equation f(x)= -2 sqrt(X+3). List in order the transformations applied to the parent function.

*October 9, 2015*

**MATH HELP PLEASE**

Find the restricted values of x for the following rational expression. x^2 + x + 6/8x^2 − 8x

*October 7, 2015*

**Algebra**

y=2-x

*October 6, 2015*

**Math**

Find the restricted values of x for the following rational expression. x^2 + x + 6/8x^2 − 8x

*October 6, 2015*

**Physics**

In a repair shop a truck engine that has mass 429 kg is held in place by four light cables (Figure 1) . Cable A is horizontal, cables B and D are vertical, and cable C makes an angle of 37.1∘ with a vertical wall. Tension in cable A is 729 N . a.What is the tension in ...

*October 2, 2015*

**school for wildlife conservation**

what is the meaning of global warming

*October 2, 2015*

**Physics**

A road heading due east passes over a small hill. You drive a car of mass m at constant speed v over the top of the hill, where the shape of the roadway is well approximated as an arc of a circle with radius R. Sensors have been placed on the road surface there to measure the ...

*October 1, 2015*

**Math**

Four thousand students at a school were asked to name their favorite pizza topping. The results were 800 Pepperoni, 1,000 Sausage, 1,200 Mushrooms, 560 Peppers, 240 Onions, and 200 Other. Your friend expresses these results in this circle graph. Your friend made a mistake, ...

*September 14, 2015*

**intermediat Algebra**

Rachel runs 7 miles in 80 minutes. At the same rate, how many miles would she run in 64 minutes?

*September 7, 2015*

**math(elmntry euclidean geometry)**

The sum of the angles of a quadrilateral is 360°. Find the conditional, draw a diagram, and state the given and conclusion. CONDITIONAL FORM: If it is the sum of the angles of a quadrilateral, then it measures 360°. DIAGRAM: Not shown, but pictures a trapezoid with ...

*September 6, 2015*

**ALgebra**

what is the maximum speed a car could be traveling in order to stop within 40ft? d=0.05V^2+1.20V

*September 4, 2015*

**Science**

Scientific methodology is what distinguishes science from other disciplines. Explain

*September 3, 2015*

**statistics**

a golf ball is selected at random from a golf bag. If the golf bag contains 4 brown balls, 9 yellow balls, and 12 orange balls, find the probability of the following event. probability the ball is brown or yellow?

*August 25, 2015*

**Math**

simplify the expression (4 square root of x)/(6-square root of x) I need help with this. I've worked it out to the point where i got (2 square root of x)/(3-square root of x), but I'm pretty sure that it can be simplified further. If what I'm thinking is right you ...

*August 25, 2015*

**Math**

simplify the expression (4 square root of x)/(6-square root of x) I need help with this. I've worked it out to the point where i got (2 square root of x)/(3-square root of x), but I'm pretty sure that it can be simplified further. If what I'm thinking is right you ...

*August 25, 2015*

**Chem**

a gas has a volumn of 36.0 L and a pressure of 750 torr when the temperature is 10 degrees celsius. what is the pressure if the volume changes to 78 degrees celsius if the amount of gas stays the same?

*August 24, 2015*

**sensitive probability plz help**

Lol what a joke of a teacher

*August 14, 2015*

**Physic**

A bullet of mass 0.05kg has a speed of 400cm|s. What is its kinectic energy? It hits a wall of which the average resistive force is 1000N, Cal.the distance penestrated by the bullet

*August 10, 2015*

**Maths**

Five-eights of the population of a village are men, one-sixth are children and the rest, 500 in number are women. How many children are there?

*August 7, 2015*

**billing and coding**

which of the following will you place below the returned address of a business envolope

*July 16, 2015*

**Math**

A boy throws a ball with a horizontal speed of 2.5 m/s at a height of 0.8 m above the ground. The Coefficient Of Restitution between ball and ground is 80%. • Calculate the x− and y−components of the ball’s velocity, immediately after its first bounce. ...

*July 12, 2015*

**Algebra**

the approximate distance, S, in feet that an object falls in t seconds when dropped from a height can be found by using the formula S=16t^2. How long will the object have fallen in 8 seconds?

*July 11, 2015*

**Geometry**

The Effel Tower in Paris is 328 feet wide at the bottom and 984 feet tall a model of the tower is 12 inches tall What is the width of the model?Round to the nearest tenth

*July 10, 2015*

**algebra 2**

Bonnie and Bruce have a rectangular swimming pool that is 6 feet wide and 10 feet long. They are going to build a tile border of uniform width around the pool. They have a 105 square feet of tile. How wide should the border be?

*July 8, 2015*

**Physics**

A 50kg sign for a local business is hung from a bar which meets a wall at right angles as shown in figure 1. The bar is 1.5 meters long, and it's mass may be neglected. The center of mass of th sign is 1.0 meters from the wall (but .50 meters from the tip of the cable) as ...

*June 24, 2015*