Wednesday

November 25, 2015
Total # Posts: 1,811

**life science**

Gls bxs kep the fossls safe and permit people to look at al sides
*July 31, 2014*

**stats**

what is the probability that a 6 digit phone number contains at least one 8?
*July 19, 2014*

**Physics**

(a) Calculate the linear acceleration of a car, the 0.280 m radius tires of which have an angular acceleration of 15.0 rad/s2. Assume no slippage. (m/s2) (b) How many revolutions do the tires make in 2.50 s if they start from rest? (rev) (c) What is their final angular ...
*June 29, 2014*

**Physics**

Two cars collide at an icy intersection and stick together afterward. The first car has a mass of 1500 kg and was approaching at 9.00 m/s due south. The second car has a mass of 700 kg and was approaching at 15.0 m/s due west. (a) Calculate the final velocity of the cars. (b) ...
*June 26, 2014*

**Statistics**

I'm taking stats online which is making it even more difficult for me and I have nowhere to begin when answering this question. 1. A pharmaceutical industry claimed that their new product will lower the cholesterol level by an average of 14.5. To verify the claim, a ...
*June 22, 2014*

**Physics**

The rocket sled shown in Figure 4.5 accelerates at a rate of 29.0 m/s2. Its passenger has a mass of 66.0 kg. Calculate the direction and magnitude of the total force the seat exerts against his body.
*June 14, 2014*

**Physics**

Howdy Jason, this is Michelle! Unfortunately I tried that, as well as just adding the forces together. Neither are the correct answer. Thanks for trying to help tho :).
*June 14, 2014*

**Physics**

Two teams of nine members each engage in a tug of war. The first team's members have average masses of 67 kg and exert average forces of 1350 N horizontally. The second team's members have average masses of 72 kg and exert average forces of 1361 N horizontally. (a) ...
*June 14, 2014*

**Algebra**

Suppose a cost-benefit model is given by y=2771x/100-x, where y is the cost for removing x percent of a given pollutant. What percent of pollutant can be removed for $36,000? Round your answer to the nearest tenth of a percent?
*June 9, 2014*

**Chem 130**

How does the energy of a principal energy level depend on the value of n? Does a higher value of n mean a higher or lower energy?
*May 13, 2014*

**Chem 130**

How do I do this? Using the symbol of the previous noble gas to indicate the core electrons, write the electron configuration for each of the following elements. (a) zirconium, Z = 40 (b) vanadium, Z = 23
*May 13, 2014*

**Calculus**

Let R be the region enclosed by the graphs y=e^x, y=x^3, and the y axis. A.) find R B.) find the volume of the solid with base on region R and cross section perpendicular to the x axis. The cross sections are triangles with height equal to 3 times the length of their base.
*May 13, 2014*

**Chem 130**

What mass of CO2 could be absorbed by 1.37 g of CaO? What volume would this CO2 occupy at STP?
*May 6, 2014*

**Chem 130**

*Thanks!
*May 5, 2014*

**Chem 130**

Thank!
*May 5, 2014*

**Chem 130**

DrBob222, I still don't understand
*May 5, 2014*

**Chem 130**

Suppose two 100.0 L tanks are to be filled separately with the gases helium and hydrogen. What mass of each gas is needed to produce a pressure of 155 atm in its respective tank at 22°C?
*May 5, 2014*

**Chem 130**

A sample of oxygen gas is collected by displacement of water at 25°C and 1.11 atm total pressure. If the vapor pressure of water is 23.756 mm Hg at 25°C, what is the partial pressure of the oxygen gas in the sample?
*May 5, 2014*

**Chem 130**

If 2.03 g of helium gas occupies a volume of 12.0 L at 22°C, what volume will 6.19 g of helium gas occupy under the same conditions?
*May 5, 2014*

**physics **

one can determine a persons center of mass by having them recline on a plank resting on two scales. A person 2m tall lies on such a plank and the scale near her head reads 405 N and the one near her feet reads 360 N. Find the center of her mass.
*May 2, 2014*

**Physics**

A pirate captain has asked you to help him engineer a new plank to have prisoners walk overboard from. He needs the plan to fall overboard with the prisoners in order not to leave any evidence behind. He has a uniform beam of length 8m and a mass of 100kg is resting on two ...
*May 2, 2014*

**physics**

You lay a board over two wooden pegs. The board has a length of 5m and weighs 25 N. it overhangs the left peg by 1m and the right by 2m. Determine the normal force that each peg exerts on the board.
*May 2, 2014*

**physics **

You are a sucker for scenic overlooks, so you want to build a house overhanging a cliff. The way you do this is by taking a 20,000 N concrete beam and hang it over the edge of the cliff with one edge at the cliff ledge and the other edge 700m away in free space. You plan to ...
*May 2, 2014*

**physics**

A ladder of mass 20kg and length 5m can be held up against a wall because the wall exerts a normal force against it. The grass has a coefficient of a static friction of 0.35. find the normal force of the wall against the ladder.
*May 2, 2014*

**physics**

A turntable with a radius of 12cm is being explored by two bugs, one at 5cm from the center and another, very dizzy beetle at 2cm from the center. The turntable is spinning at 7 rad/s. Which bug will have the greater angular momentum?
*May 2, 2014*

**physics**

You always carry 3 wristwatches. One of them is synchronized with your labs atomic clock. Another is running low on battery and is 3 minutes behind, while the third watch is running 6 minutes fast. All were set to the same time when purchased. List the comparative angular ...
*May 2, 2014*

**Physics**

A figure skater spinning in a circle and dazzling the Olympic judges brings her arms together for a final flourish. 1. Does her angular momentum increase, decrease, or stay the same after she pulls her arm in? 2. Does her angular velocity increase, decrease, or stay the same ...
*May 2, 2014*

**Physics **

A rolling barrel with initial velocity 20 m/s encounters a hill 10m tall to slow it down 1. state where its angular speed is 0 2. state where its rotational kinetic energy will be 0 3. state where its translation kinetic energy will be 0 4. for each of the two flat surfaces ...
*May 2, 2014*

**Physics**

You have a crane boom with a mass of 10000kg being held up by a cable and holding a weight of 2500kg. A. Find the torque caused by the weight B. Find the torque caused by the cable C. Find the torque caused by any other force holding it in equilibrium
*May 2, 2014*

**Physics **

You wonder what would happen if you fired a 9.109e-31kg particle moving at 20 m/s in the x direction of a 1.672e-24kg particle moving at 12 m/s at 110 degrees from the x direction. The lighter particle hits the screen at a 100 degree angle from the x direction. What is the ...
*May 2, 2014*

**Physics**

You shoot your enemy's reflection in the mirror while playing paintball. The y axis is perpendicular to the mirror. The mirror has a mass of 1kg and the paintball has a mass of 0.05 kg. The paintball hits the mirror at a speed of 8 m/s at an angle of 25 degrees from the ...
*May 2, 2014*

**Physics **

Instead of standing in the back of the lane and rolling the ball toward the pins like most people, you place a 5kg bowling ball at rest at the back of the lane and try to hit it toward the pins with a perfectly elastic collision using a 1kg ball rolling at 5 m/s from a 25 ...
*May 2, 2014*

**Physics**

A 25,000kg bowling ball moving at 40 m/s on a path angled at 17 degrees hits a 10000kg bowling ball moving at 25 m/s on a path angled at 60 degrees causing the lighter ball to be deflected of to an 65 degree angle. Assuming this is a two dimensional, perfectly elastic ...
*May 2, 2014*

**Calculus**

Consider the differential equation dy/dx=xy-y. Find d^2y/dx^2 in terms of x and y. Describe the region in the xy plane in which all solutions curves to the differential equation are concave down.
*May 1, 2014*

**Physics **

You have a crane boom with a mass of 10000kg being held up by a cable and holding a weight of 2500kg. 1. Find the torque caused by the weight 2. Find the torque caused by the cable 3. Find the torque caused by any other force holding it in equilibrium
*April 30, 2014*

**Physics**

Your teenage kid finally gets his drivers license. He takes off in your brand new car that weighs 2000kg at 47m/s when he hits a parked semi that weighs 40000kg. They plow forward in a perfectly in elastic fashion in the same direction. What is the velocity of the wreck?
*April 26, 2014*

**Physics**

Your teenage kid finally gets his drivers license. He takes off in your brand new car that weighs 2000kg at 47m/s when he hits a parked semi that weighs 40000kg. They plow forward in a perfectly in elastic fashion in the same direction. What is the velocity of the wreck?
*April 25, 2014*

**Physics **

In one dimension, a 12 kg ball moving to the right at 9 m/s collides with a 4kg ball moving to the left at 3 m/s. The collision is perfectly elastic. Find the final velocities of both balls.
*April 25, 2014*

**Physics**

A 25000kg bowling ball moving at 40 m/s hits a 10000kg bowling ball moving at 25 m/s from behind. It is a perfectly elastic collision, so what are the final velocities of the two balls?
*April 25, 2014*

**Physics **

In one dimension, a 5g ball is moving to the right at 7 m/s collides with an 8g ball moving to the left at 4 m/s for a perfectly elastic collision. What is the final velocity of both balls? I just don't understand the whole left and right thing. I have already worked it ...
*April 25, 2014*

**College Physics**

Can someone check my answers for two and help me with the third? 1) A mass m at the end of a spring of spring constant k is undergoing simple harmonic oscillations with amplitude A. Part (a) At what positive value of displacement x in terms of A is the potential energy 1/9 of ...
*April 25, 2014*

**math**

An item originally cost $16.95 and is on sale or 22%. Find the cost of the item. Explain each step
*April 23, 2014*

**chemistry**

A sample of helium at 20 °C occupies a volume of 3.63 L at a pressure of 3.07 atm. What volume does this helium sample occupy if the pressure is reduced to 2.43 atm while maintaining the temperature at 20 °C?
*April 23, 2014*

**Algebra**

finding the equation to the perpendicular lines. y=x+4; (-7,1)
*April 18, 2014*

**Calc**

Last question! Thanks! Given f(3)=4 and f'(3)=5 find g'(3) where g(x)= 5x/f(x)
*April 17, 2014*

**Calculus**

Given f(3)=4 and f'(3)=5, find g'(3), where g(x)=8x.f(x)
*April 17, 2014*

**physics**

a window easher pushes his brush up a vertical window at constant velocity by applying a force F as shown below. The brush weighs 12 N and the coefficient of the kinetic friction is 0.2. find the magnitude of force F.
*April 17, 2014*

**physics**

Two blocks are connected by a light string that passes over a massless, frictionless pulley as shown. The coefficient of friction between the 4kg block and the surface is 0.4. Find the acceleration of the system and the tension in the string.
*April 17, 2014*

**English**

This is the part I am having trouble with: This led Schultz to leave the shells in random places around her home. She would put them where she was sure to see them and every so often, she picked one up and squeeze it, “grateful for the reminder to live a pinch-me life.&#...
*April 16, 2014*

**English**

My Essay: A Mother’s Sense of Wonder To lose a loved one is very hard to bear, but to lose a parent can be very heart-wrenching for a child at any age. Connie Schultz wrote “My Mom’s Wonderful, ‘Pinch Me’ Life,” which was published in 2012, in the...
*April 16, 2014*

**College Math**

Thank you very much!
*April 16, 2014*

**College Math**

Find the derivative of the following functions: a) f(x)=(3x^2-6 )/(x+2) b) g(x)=sin(e^2 +5x) c) j(x)=6xe^x d) Your velocity is v(t)= t^2 = 1 for 0≤ t ≤ 4. Find or estimate the distance traveled during this time.
*April 16, 2014*

**math**

If I had to divide 680 cm^3/s by 1.767 cm^2 and needed an answer in m/s..how would I do that? Just cancel out two cm's and then divide by 0.01?
*April 15, 2014*

**College Physics**

A uniform stationary ladder of length= 5.1 m and mass= 15 kg leans against a smooth vertical wall, while its bottom legs rest on a rough horizontal floor. The coefficient of static friction between floor and ladder is μ = 0.41. The ladder makes an angle θ = 51° ...
*April 11, 2014*

**Physics **

A cannon launches a ball with the initial speed of 210 m/s at a 70 degree angle. 1. How high will the cannonball go? 2. If the cannonball has a mass of 25kg how much work does it take to launch the cannonball to that height?
*April 11, 2014*

**Physics**

Standing at the edge of a cliff 240 m tall. You throw a ball into the air one directly upward at 5 m/a and another downward at -5 m/s. Use conservation energy to show that they will have the same speed at the bottom. I know I have to do it twice.. And it should seem simple. I...
*April 11, 2014*

**physics help!**

A uniform stationary ladder of length= 5.1 m and mass= 15 kg leans against a smooth vertical wall, while its bottom legs rest on a rough horizontal floor. The coefficient of static friction between floor and ladder is μ = 0.41. The ladder makes an angle θ = 51° ...
*April 10, 2014*

**Physics**

I think I got it. c) ω0 t + (0.5*α*t^2) d) 911.3 Can you just double check this?
*April 2, 2014*

**Physics**

I already figured out the answers to some but I need help with two more. 1) A disk with an initial angular velocity ω0 = 4.5 rad/s experiences a constant angular acceleration of α = 7.5 rad/s2 for time t = 15 s. Please answer the following questions. ω0 = 4.5 ...
*April 2, 2014*

**Physics**

Thanks for taking a look! A baseball of mass m1 = 0.46 kg is thrown at a concrete block m2 = 8.25 kg. The block has a coefficient of static friction of μs = 0.81 between it and the floor. The ball is in contact with the block for t = 0.165 s while it collides elastically...
*March 25, 2014*

**Math**

One of my questions say 16, base 4. It says to write it as an exponent but which one is which?
*March 19, 2014*

**Physics**

(Need Help Only For Last Question! I figured out the first two.) A car of mass m = 1130 kg is traveling down a θ = 11 degree incline. When the car's speed is v0 = 11 m/s, a mechanical failure causes all four of its brakes to lock. The coefficient of kinetic friction ...
*March 18, 2014*

**math**

If a store owner buys a microwave for $200 and sells it for $275. What is the percent markup based on cost?
*March 15, 2014*

**English**

Thanks... And Post in the same name? If your referring my husbands posting yesterday that he used my account. I apologizes for that. It wasn't me. Thanks again for the help. And it does help. Have a great day!!!
*March 14, 2014*

**English**

Yes you did which I am extremely grateful. :) But now I need to make it longer and into two paragraphs. I am drawing a blank as to what to add to complete the task.
*March 14, 2014*

**English**

I need to make this into two paragraphs and make it a little longer. I am drawing a blank. Can someone please help me. My study habits consist of reading aloud, note taking and last minute cramming. The reading aloud and note taking have always worked well for me. Last minute ...
*March 14, 2014*

**Physics**

A traffic light is hanging from two cables tilted at 37 and 42 degrees. If it has a mass of 2.3 kg find the tension in each cable.
*March 14, 2014*

**Physics**

A freight train has a mass of 4.78 * 10^7 kg. the locomotive provides a force of 1.3 * 10^6 N and the brakes provide a force of -3.2 * 10^3 N. 1. How long will it take for the train to accelerate to it's maximum speed of 15 m/s? 2. The train accidentally stumbles into an ...
*March 14, 2014*

**English**

Can someone help me figure out what me figure out what my teacher is talking about here. I had to write a self introduction and she told me that I had spelling errors and redundant words. I don't see where she's talking about. My name is Devyn Donahue. I am originally ...
*March 13, 2014*

**English**

Got it!! Thank you so much for your help.
*March 13, 2014*

**English**

Does this sound any better? My study habits consist of reading aloud, note taking and last minute cramming. The reading aloud and note taking has always worked well for me. Last minute cramming hasn’t work very well. I seem to always draw a blank on test day. I found ...
*March 13, 2014*

**English**

Hi, Can someone help me with my online Psychology assignment? She is a stickler for punctuation and grammar. I have not taken English yet. I need all the help I can get. The following is my assignment and response. For this assignment, I'd like you to think about your ...
*March 13, 2014*

**math**

Help pleaseeee The Hotel Regal has 500 rooms. Currently the hotel is filled. The daily rental is $ 400 per room. For every $4 increase in rent the demand for rooms decreases by 8 rooms. Let x be the number of rooms that are being rented in the hotel. What should x be so as to ...
*March 5, 2014*

**Science**

Umm may I ask Daniel Brown if you are in Commonwealth Connection Academy?
*March 4, 2014*

**Science**

I am not sure because I am trying to check the same quiz :(((
*March 4, 2014*

**English**

Hi, can you help me with this please? I am taking a online Psychology course. The teacher is a stickler about your punctuation and grammar. The following is my assignment and then my response. For this assignment, I'd like you to think about your study habits using the ...
*March 3, 2014*

**(I need alot of help in) Physics**

Okay its starting to make sense to me now. Thanks for taking the time to explain this to me!
*February 28, 2014*

**(I need alot of help in) Physics**

Im starting to guess that for question one would velocity be independent of mass I asked someone else about two and they said the slopes should be neg because dv/dt = -g and since gravity is always downward then slope is neg. As for the property I'm still not sure.
*February 28, 2014*

**(I need alot of help in) Physics**

So in physics lab we did an experiment with a cart with two different masses on a air track (practically eliminating kinetic friction). The track was tilted at 4 degrees. Using 4 photo-gates I got the speed of both gliders and the height at each point. I made two graphs making...
*February 28, 2014*

**behavioral statistics**

How could you use standard scores and the standard distribution to compare the reading scores of two students receiving special reading resource help and one student in a standard classroom who does not get special help?
*February 25, 2014*

**Physics**

You are general in the Napoleonic wars. You are on top of a plain 12m talk and you have a cannon tht can shoot a cannonball out at 350 m/s. 800 m away is a thick forest that you cannot see into but one of your scouts in a hot air balloon has just signaled to you that an enemy ...
*February 22, 2014*

**Physics**

You are a general in the Napoleonic wars. An enemy fort 10m tall is located 1000m from your cannon. Your cannon expert is insisting that you will get the best results at an angle of 25 above the horizontal. Your cannon is located on a hill 10m tall. You have soldiers storming ...
*February 22, 2014*

**Physics**

You are a general in the Napoleonic war. The battle has taken you to a trench 7m deep. You have a mortar that will fire an explosive at a speed of 200 m/s at an angle of 80. You have a low flying reconnaissance airplane scouting out the enemy troops at a height of 500 m. Your ...
*February 22, 2014*

**Physics**

Suppose you are a general in the Napoleonic wars. You are no top of a plain 50 m high overlooking the enemy soldiers. You now have a brand new cannon that will decimate the enemy. Unfortunately in the christening process you used some rather cheap grade champagne and all the ...
*February 22, 2014*

**Physics**

A ball is thrown upward in two dimensions with an initial speed of 17 Zlugs per mega handle(made up) near the surface of the planet earth. What will be the y component of the balls velocity at the peak of its trajectory?
*February 20, 2014*

**Physics **

You are general in the Napoleonic wars. You are on top of a plain 12m talk and you have a cannon tht can shoot a cannonball out at 350 m/s. 800 m away is a thick forest that you cannot see into but one of your scouts in a hot air balloon has just signaled to you that an enemy ...
*February 19, 2014*

**Physics **

You are a general in the Napoleonic wars. An enemy fort 10m tall is located 1000m from your cannon. Your cannon expert is insisting that you will get the best results at an angle of 25 above the horizontal. Your cannon is located on a hill 10m tall. You have soldiers storming ...
*February 19, 2014*

**Physics **

You are a general in the Napoleonic war. The battle has taken you to a trench 7m deep. You have a mortar that will fire an explosive at a speed of 200 m/s at an angle of 80. You have a low flying reconnaissance airplane scouting out the enemy troops at a height of 500 m. Your ...
*February 19, 2014*

**Physics**

Suppose you are a general in the Napoleonic wars. You are no top of a plain 50 m high overlooking the enemy soldiers. You now have a brand new cannon that will decimate the enemy. Unfortunately in the christening process you used some rather cheap grade champagne and all the ...
*February 19, 2014*

**Physics**

A ball is thrown upward in two dimensions with an initial speed of 17 Zlugs per mega handle(made up) near the surface of the planet earth. What will be the y component of the balls velocity at the peak of its trajectory?
*February 19, 2014*

**Physics**

A cannon shoots a cannonball with an initial speed of 25 m/s at an angle 13. 1. What is the x component of the cannonballs initial velocity Vox? 2. What is the y component of the cannonballs initial velocity Voy? 3. What will be Vy, the y component of the cannonballs final ...
*February 19, 2014*

**Physics**

A cannon fires a free projectile at an angle 85 from the ground. The cannonball has a speed of 150 m/s and it is launched from a hill 20 m above the plain where it will land 1. What is the x component of the cannonballs initial velocity 2. What is the y component of the ...
*February 19, 2014*

**Math**

1/25
*February 19, 2014*

**Physics **

A cannon fires a free projectile at an angle 85 from the ground. The cannonball has a speed of 150 m/s and it is launched from a hill 20 m above the plain where it will land 1. What is the x component of the cannonballs initial velocity 2. What is the y component of the ...
*February 17, 2014*

**Physics **

A cannon shoots a cannonball with an initial speed of 25 m/s at an angle 13. 1. What is the x component of the cannonballs initial velocity Vox? 2. What is the y component of the cannonballs initial velocity Voy? 3. What will be Vy, the y component of the cannonballs final ...
*February 17, 2014*

**Physics**

A ball is thrown upward in two dimensions with an initial speed of 17 Zlugs per mega handle(made up) near the surface of the planet earth. What will be the y component of the balls velocity at the peak of its trajectory?
*February 17, 2014*

**Advanced Maths **

A reservoir is fed by two pipes of different diameter. The pipe with the larger diameter takes three hours less than the smaller pipe to fill the reservoir. if both pipes are opened simultaneously, the reservoir can fill in two hours. Calculate how long it takes the pipe with ...
*February 15, 2014*

**Physics **

A jet plane has a takeoff speed of Vto=125km/h (34.72 m/s) and it's engines can power it to accelerate with an average acceleration of 5.6 m/s^2. A.) what length of runway will it need to take off safely? B.) suppose it had an available runway length of only 75m. What ...
*February 8, 2014*

**physics**

Standing at the edge of a cliff 240 m tall. You throw a ball into the air one directly upward at 5 m/a and another downward at -5 m/s. Use conservation energy to show that they will have the same speed at the bottom. I know I have to do it twice.. And it should seem simple. I ...
*February 8, 2014*

**physics**

A car is moving down a highway at -15 m/s and accelerating at 3 m/s^2. If it's initial position is at x = 0 m where will it be after 3 seconds?
*February 8, 2014*