# Posts by ruby

Total # Posts: 248

**physics**

A box is resting on a table frictionless). Determine the weight of the box and the normal force acting on it. (a) If the box was pushed down, with a force of 40N, determine again the normal force acting on the box. (b) If the box was pulled up with a force of 40N, what now is ...

*July 22, 2008*

**physics**

!* =)

*July 22, 2008*

**physics**

Yes! thank you both! this really helps1

*July 22, 2008*

**sorry!**

For this problem: A person throws a ball upward with an initial velocity of 15 m per second. In order to calculate how high the ball goes, drwls gave me this formula below: It travels upwards until the vertical velocity component becomes zero. The calculaitons are below: (1/2)...

*July 22, 2008*

**physics**

How would you reword the terms of this equation: (1/2)M Vo^2 = M g H Where H is the maximum height above the thrower's hand. H = Vo²/(2 g) = 11.5 m Could you substitute the letters H & M with Y, Yo, V, Vo, G, T, or use any of these four newton's equtions: V = Vo...

*July 22, 2008*

**physics**

thanx =) for all your help!

*July 21, 2008*

**question?**

so, then to calculate the distance, the formula would be 50 m =(1/2)(9.8m/s^2)(t^2) and you would neglect the negative signs, but then instead of dividing 50m by -90.8m/s^2, how would u use that formula to find the value of t? Sorry, i am just really confused regarding all of ...

*July 21, 2008*

**physics**

-Suppose that a person is standing on the edge of a cliff 50 m high, so that the ball in his/her hand can fall to the base of the cliff. Questions (a)-How long does it take to reach the base of the cliff? (b)- What is the total distance traveled by the ball? Attempted Answers...

*July 21, 2008*

**math**

1 kg is equivilant to about 2.2 lbs. So if you would give 0.1 g per kg, you would convert this to lbs which would give you approx. 0.045 gram/lb. Now simply multiply. 0.045 x 50 = 2.25 grams. =)

*July 21, 2008*

**physics**

thanx so much! im finally starting to get this!

*July 21, 2008*

**physics**

-A person throws a ball upward into the air with an initial velocity of 15 m per second. - How could you calculate how high the ball goes and how long the ball is in the air before it comes to the thrower's hand?

*July 21, 2008*

**physics**

THANK YOU SOO MUCH!! THIS REALLY HELPED!!!

*July 20, 2008*

**physics**

earlier in this forum, marina asked the same question as i did. unfortunately, someone did answer, very clearly, but for some reason i remained to be a little lost. Here is the question: A car traveling 90 km/h is 100 m behind a truck traveling 75 km/h. How long will it take ...

*July 20, 2008*

**Physics**

THANX SOO MUCH!! YOU ARE AWESOME!!

*July 20, 2008*

**Physics**

Physics Homework _____________________________________________________________ 1.) A particle at t 1 = -2.0 s is at x 1 = 3.4 cm and at t 2 = 4.5 s is at x2 = 8.5 cm. What is its average velocity? Can you calculate its average speed from this data? ...

*July 20, 2008*

**physics ---- more help please**

this answer is correct but i need the mathematical law needed to solve this problem.

*July 16, 2008*

**physics**

the question is this: suppose you want to design an air-bag system that can protect the driver in an head-on collision at a speed of 100 km/h. estimate how fast the airbag must inflate to protect the driver-- I GOT THE CORRECT ANSWER TO THIS ONE ALREADY. now the second ...

*July 16, 2008*

**HCA**

What are the consequences of seperarating mental health from physical health caare

*June 23, 2008*

**ETH**

Thank you for your advice. I like how that sounds The paper is a challenge I am a very non racial person and the town I live in is small and really has non of the issues I need to write about, that I am aware of at least, I am sure some exist...

*April 3, 2008*

**ETH**

We are writing a paper on "Race in your Community" and I have had a hard time getting going because I live in a small town with really one ethnic group, however as I dug I started finding some minority groups are here, what I am looking for is for some opinions on my...

*April 3, 2008*

**math**

A family spends 20% of its monthly income on food, 23% on rent, and 42% on other expenses and saves the balance. If the family saves $360 per month, what is its monthly income?

*March 18, 2008*

**physics.**

A steel beam is used in the construction of a skyscraper. By what fraction (change in L)/Lo does the length of the beam increase when the temperature changes from that on a cold winter day (-15 degree F) to that on a summer day (+ 105 degree F)? I got 0.00144 for the answer, ...

*February 10, 2008*

**economics**

what is a country's excess quantity of demand to a nation's? exports or imports

*February 9, 2008*

**problems faced in conserving kalimantan rainforest**

The tropical rain forest aer home to over_of the world's species of life.

*December 23, 2007*

**Algebra**

Find the value of y in each formula if x= -3. y + 1 = 2(x - 5) Substitute -3 for x. The first step leaves you with this: y + 1 = 2 * (-8) = -16 Now solve for y by subtracting 1 from each side of the equation.

*July 7, 2007*

**Algebra**

Solve problem by showing necessary steps to resolve. 0.06q + 14 = 0.3q - 5.2 Subract 0.06 q from both sides. 14 = 0.24q - 5.2 Add 5.2 to both sides 19.2 = 0.24 q Finally, divide both sides by 0.24 You will end up with q on one side of the equation and a number which is the ...

*July 7, 2007*

**Math**

What is the value of y if x = -3? y = 1 = 2(x-5) Plug in -3 for x, in the equation for y, and see what you get. I think you copied the problem wrong. Is the first = sign supposed to be a + or - sign? If not, you have already stated that y = 1. That cannot be true when x = -3. ...

*June 29, 2007*

**Earth science**

I would like to comfirm that the 4 cycles on Earth are: carbon, water and rock. I think the 4th one is the biosphere but am not sure as the biosphere contains all attributes necessary (including the atmosphere)for life to exist. Am I on the track? I do understand that the ...

*April 25, 2007*

**geology**

there are 3 rock types:(a)igneous,(b)sedimentary,(c)metamorphic.If rock (a)were to cut across both other rocks and (c) is the oldest rock, describe the new relationship between the rocks. are you doing 103 by any chance im stuck on this q as well and thought it might be asking...

*April 20, 2007*

**biology**

in addition to the above a labelled diagram is also required to show the product cells derived from this cell at the telophase 2 stage of meiosis.there is no crossng over.what differences would there be in the product cells at telophase 2 of meiosis if there had been one ...

*March 24, 2007*

**biology**

Help required, Gametes are produced in the process of meiosis. In humans, one pair of autosmes (chromosome 4) has a short arm and a long arm. On the short arm is a gene for Huntington disease (H) and on the long arm is a gene for red hair(R). Draw a labelled diagram to show ...

*March 24, 2007*

**biology**

Help needed to draw a mating diagram where L is the dominant gene for the digestion of lactose and shows the crosses between two heterozygotes and wiht the the phenotypic and genotypic ratio of the offspring in the F1 generation. I also need to know the phenotypic prportions ...

*March 13, 2007*

**chemistry**

help required in calculating the pH value of a .84 mols per litre solution of sulfuric acid. I understand that pH = -log 10 (2x 0.84), I am not very experienced with logs and need assistance as to which keys to press on the scientific calculator in relation to the logs. thank ...

*March 6, 2007*

**chemistry**

I am in the process of calculating the hydrogen ion concentration in a .25litre solution of sulfuric acid,.21g of sulfuric acid was disolved in water to make the solution. I have calculated the molarity of the acid to be 2.14x10^-3 mol per litre. I also need help in ...

*March 5, 2007*

**chemistry**

I require assistance with the drawing of the lewis structures for hydrogen cyanide and cyanogen. I have already drawn the structured molecular formulas and am now stuck. H:C:::N: :N:::C:C:::N:

*March 5, 2007*

**chemistry**

In the compound tocainide I need to identify the two groups of atoms/groups that are linked with its binding to receptor cells in the human body by hydrogen bonding. I have understood the two groups to be alcohol and acid but am stuck on the next part. Hmmm. What alcohol. I ...

*February 15, 2007*

**chemistry**

I would like my equation checked, sodium cyanide and water.I have worked the balanced equation as: NaCN+H20=NaOH+HCN. If you want the molecular equation this looks good to me. Actually, it's the CN^- that is hydrolyzed (reacts with water) and the ionic equation is CN^- + ...

*February 8, 2007*

**chemistry**

I need help in drawing a structual formula for hydrogen cyanide(HCN)and cyanogen(CN)2, the drawing has to bear in mind the valencies of hydrogen(1),nitrogen(3) and carbon (4), any help appreciated H:C:::N: :N:::C:C:::N: Check my thinking. The previous one, too.

*February 6, 2007*

**chemistry**

help needed in drawing the diagram to show how hydrogen has numerous spectral lines I also need help with this question.... ---------------- ---------------- ---------------- ---------------- ---------------- -------------------- Each line above represents an energy level for ...

*February 6, 2007*

**Science**

mols of HCl= 0.1N X 0.5L=0.05 mols of HCl Therefore, number of mols of 2N NaOH needed to obtain pH 6.8: 0.05 mols HCL/2 = 25 mL Is this right? answered below.

*February 5, 2007*

**Science**

How much sodium hydroxide, at what concentration, do I need to add to 500 mL of 0.1 N HCL to obtain pH 6.8. How do you calculate this? pH = -log(H^+) M HCl = N HCl mols = M x L. After you know mols HCl you have, then make a solution of NaOH and calculate how much of that must ...

*February 5, 2007*

**physics**

Assistance required as to why visible light is not emitted when infrared radiation falls on fluorescent materials.

*February 5, 2007*

**chemistry**

addtional information: the diameter of the oil film on the water is 40cm^2 see my post.

*February 4, 2007*

**chemistry**

I have a problem that I need help with. The diameter of the oil molecule has to be calculated and presented in scientific notation. The data in the questions tells me that drop of oil(volume 0.05cm ^3) is released from a dropper onto the surface of the water.The film of oil ...

*February 4, 2007*

**math[fractions]**

how would u multiply two fractions ex. 2 2/3 times 3 5/6 First, make each one an improper fraction. To do this, multiply the denominator by the whole number in front of it and then add the numerator. Put all of that on top of the denominator: 3*2=6 6+2=8 2 2/3 = 8/6 = 4/3 6*3=...

*January 23, 2007*

**mummification**

what was the substance used to stuff nostrils? The ancient Egyptians stuffed the nostrils with resin or wax. http://209.85.165.104/search?q=cache:3ghP1ChFOJYJ:www.touregypt.net/featurestories/mummification.htm+mummification+nostrils+resin&hl=en&gl=us&ct=clnk&cd=1&ie=UTF-8

*January 23, 2007*

**Science 9**

2.0kg block of iron transfers 180,000j to the atmosphere around it. If its initial temperature was 350 celius what is it's final temperature? If you know the specific heat of iron, you can use Q = mc(delta T).

*December 30, 2006*

**Geography**

Flordia

*October 4, 2006*