Thursday

September 29, 2016
Total # Posts: 1,007

**Physics**

The two strands of the helix-shaped DNA molecule are held together by electrostatic forces as shown in the Figure 16-44 in the textbook. Assume that the net average charge (due to electron sharing) indicated on H and N atoms is 0.2e and on the indicated C and O atoms is 0.4e. ...

*February 4, 2013*

**math**

the largest value of n for which 10^n evenly divides 2^9*15^2*35 is a)2 b)3 c)4 d)5 e)6

*January 31, 2013*

**Physics (As Level) 12 Grade**

Yes, thank you. I worked it out, after a few minutes. Anyway, thank's a lot :)

*January 30, 2013*

**Physics (As Level) 12 Grade**

Not really helping much. A slightly worked example would be effective. But thanks anyway.

*January 30, 2013*

**Physics (As Level) 12 Grade**

2) An aircraft lands on a runway at a speed of 40 meters per second (ms^-1) and brakes to a halt in a distance of 860m. Calculate a) The Braking time. B) The deceleration of the aircraft.

*January 30, 2013*

**Physics**

A 70 kg person stands on a 30 kg platform and pulls on a massless rope with a force of 400 N. The rope passes around a pulley attached to a support (roof), and then around a second pulley attached to the platform before being anchored to the support (roof). All sections of the...

*January 22, 2013*

**physics**

In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner?

*January 13, 2013*

**Statistics**

Lol mate. This question is too long to be answered by us. Do it yourself, this is college level stuff.

*December 29, 2012*

**Physics**

What is the magnitude of the electric field 0.3 m from a 10-4 C point charge?

*December 4, 2012*

**Programing using Raptor ( Computer Logic)**

Create a program that determine the shipping cost for an order based on the following table: From $0.00 $20.00 $50.00 $75.00 To $19.99 $49.99 $79.99 $1000.00 Price $2.95 $3.95 $4.95 Free

*December 3, 2012*

**CHM**

How to balance the following equation: Na(s) + H2O(l) yields?

*November 27, 2012*

**physics**

Since momentum is conserved vf=1.3044

*November 19, 2012*

**Trig**

Suppose you would like to cross a 200-foot wide river in a boat. Assume that the boat can travel 35 mph relative to the water and that the current is flowing west at the rate of 5 mph. What bearing should be chosen so that the boat will land at a point exactly across from its ...

*November 18, 2012*

**Trig**

Suppose you would like to cross a 209-foot wide river in a boat. Assume that the boat can travel 32 mph relative to the water and that the current is flowing west at the rate of 6 mph. If the bearing chosen is chosen so that the boat will land at a point exactly across from ...

*November 18, 2012*

**math**

A solar home contains 3.50 multiplied by 105 kg of concrete (specific heat = 1.00 kJ/kg·K). How much heat is given off by the concrete when it cools from 29 to 20°C?

*November 13, 2012*

**Physics**

(a) Suppose that on the moon an astronaut hit a golf ball so that it left his club at a speed of 45ms-1, at an angle of 20degrees to the horizontal. calculate the time of flight of the ball. (b) calculate the horizontal distance travelled by the ball before landing

*October 28, 2012*

**Calculus 1**

differentiate f(x)=(1+sinˆ2x)ˆ6

*October 15, 2012*

**Calculus 1**

differentiate f(x)=(sinˆ2x)/(cosx)

*October 15, 2012*

**CHM**

freezing point of cyclohexane...yes I am using the depression of freezing point method

*October 10, 2012*

**CHM**

Some of the cyclohexane solvent vaporized during the temperature versus time measurement. Will this loss of cyclohexane result in its freezing point being recorded as too high, too low or unaffected? Explain. Please someone explain this to me I don't understand it...Thank you

*October 10, 2012*

**Math**

Given the following statistical list: 13,17,19,22,25,27,29,29,32,and 33. Assuming a desired "Confidence Level" of 95%, find the confidence interval for the above scores. 19.8 < u(mean)< 29.4 14.6 < u < 33 13.4 < u < 22.7 11.1 < u < 18.5 I have...

*October 2, 2012*

**physics**

A 140-W heater was placed in 2.00 kg of methanol and turned on for exactly 1 min. The temperature increased by 3.54°C. Assuming that all the heat is absorbed by the methanol, calculate the molar heat capacity of methanol.

*September 25, 2012*

**Chemistry**

A 1.00 g sample of enriched water, a mixture of H2O and D2O, reacted completely with Cl2 to give a mixture of HCl and DCl. The HCl and DCl were then dissolved in pure H2O to make a 1.00 L solution. A 25.00 mL sample of the 1.00 L solution was reacted with excess AgNO3 and 0....

*September 21, 2012*

**Math**

A diver is working 10 feet below the surface of the water. The gap between the water and the deck of his support barge is 1/8 of the total length of the air hose and 2/3 of the total length remains on the reel. What is is maximum working depth?

*September 13, 2012*

**7th grade math**

25, base 5

*September 11, 2012*

**Physics**

a) The horizontal component of any velocity remains constant as it goes through the air, so the horizontal component of the initial velocity would still be 8.8i. The distance can be calculated using the formula Xf=Vx*t: Xf=8.8*2.7=23.76 b)Maximum height is given by the formula...

*September 1, 2012*

**math**

first you need to set it equal to zero 3x^2-48=0 then we factor we can pull the 3 out becasue 3 goes into 48 and 3x^2 so we would get something like this 3(x^2-16)

*August 29, 2012*

**Maths**

A garage bought 55000 litres of petrol for 86 pence a litre and sold it for 96 pence a litre calculate how much garage paid for petrol.

*August 19, 2012*

**Health**

D is incorect I put it on my test was wrong

*August 4, 2012*

**health!**

Correct Answer is Catastrophizing. C

*August 3, 2012*

**HEALTH**

of Course I mean A !!

*August 1, 2012*

**HEALTH**

B is correct answer ! Body Mass Index (BMI) is a number calculated from a person's weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.

*August 1, 2012*

**english**

Think of the action that the subject is performing.

*July 30, 2012*

**math**

If W(p)is congruent to 0(mod p), then p is a Wilson Prime. Show that 5 and 13 are Wilson Primes.

*July 30, 2012*

**math **

find the remainder when 13^16 + 17^12 is divided by 221.

*July 30, 2012*

**Statistics**

The amount of a monthly phone bill is normally distributed with a mean of $60 and a standard deviation of $12. Fill in the blanks: 68% of her phone bills are between $______________ and $______________.

*July 23, 2012*

**phsycs**

2cw=340*3/2=510m but the answer given is 514.5m?

*July 19, 2012*

**phsycs**

A person shouts in a canyon. 3 s later they hear the echo. How far away is the canyon wall from which the sound wave was reflected? how do i do this problem?

*July 19, 2012*

**physics**

Bobpursley Answered your question before too. Tried to attempt it. But my physics knowledge is limited.

*July 5, 2012*

**Physics (work and springs)**

A 4kg box is compressed 50cm on a spring (k=800 N/m) and then slides across a horizontal floor. If (u=0.4) between the box and the floor... A) how much work is done? B) assuming the frictional force is constant, how far will the box slide before it comes to a stop?

*July 2, 2012*

**chemistry**

What is the molarity of a saline solution that contains 0.900 g NaCl (58.44 g/mol) dissolved in 100.0 ml of a solution?

*June 24, 2012*

**Physics**

(a) If the length of the Achilles tendon increases 0.55 cm when the force exerted on it by the muscle increases from 2200 N to 6000 N, what is the "spring constant" of the tendon? N/m (b) How much work is done by the muscle in stretching the tendon 0.55 cm as the ...

*June 8, 2012*

**Math**

factor out the greatest common factor -2p+40

*June 4, 2012*

**physics please help **

An astronaut stands at a position on the Moon such that Earth is directly overhead and releases a Moon rock that was in her hand. (c) What is the gravitational force exerted by the Earth on the same 2.7-kg rock resting on the surface of the Moon? answer in mN I keep ...

*May 25, 2012*

**physics**

Thanks Elena, but I tried the answer and its wrong I don't know why. Could you please help me. Thanks.

*May 25, 2012*

**physics**

Sorry I keep recalculating, but i keep getting 4.36 m/s and thats wrong I don't know what I am doing wrong.

*May 23, 2012*

**physics **

A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What...

*May 23, 2012*

**physics**

A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What...

*May 22, 2012*

**physics**

A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What...

*May 22, 2012*

**physics please someone help**

Peggy drives from Cornwall to Atkins Glen in 52 min. Cornwall is 75 km from Illium in a direction 26° west of south. Atkins Glen is 27.1 km from Illium in a direction 16° south of west. Use Illium as your origin. (a) Draw the initial and final position vectors. (Do ...

*May 20, 2012*

**Physics **

Peggy drives from Cornwall to Atkins Glen in 52 min. Cornwall is 75 km from Illium in a direction 26° west of south. Atkins Glen is 27.1 km from Illium in a direction 16° south of west. Use Illium as your origin. (a) Draw the initial and final position vectors. (Do ...

*May 20, 2012*

**Physics**

Peggy drives from Cornwall to Atkins Glen in 52 min. Cornwall is 75 km from Illium in a direction 26° west of south. Atkins Glen is 27.1 km from Illium in a direction 16° south of west. Use Illium as your origin. (a) Draw the initial and final position vectors. (Do ...

*May 20, 2012*

**physics**

a satellite completes one revolution of a planet in almost exactly one hour. at the end of an hour , the satellite has traveled 2.0x10^7 meters and is only 10 meters away from its starting point. What is the numerical value of the satellite's average velocity after that ...

*May 19, 2012*

**Math**

Question 2 For the function f(x) = 3x2-2x-7, find f(2). Answer f(2) = 13 f(2) = 25 f(2) = 1 f(2) = 1/2 3 points Question 3 One day you work 3 hours and your boss gives you $22. Another day after working 4 hours your boss gives you $33. Yesterday after working 5 hours you get $...

*May 18, 2012*

**science**

sugar concentration os 10g/100ml given a teaspoon weighs 4 g calculate how many teaspoons of sugar you would consume if you drank a 600ml bottle of soft drink

*May 10, 2012*

**Environmental Economics**

Can forest harvesting still be ineﬃcient even where tenure is given on a individual basis and is secure? Why or why not? Please answer this question in 3 sentences or less.

*May 7, 2012*

**pre-calculus**

i'm so confused right now. can u solve one question for me so i can try the rest? thank you!

*April 22, 2012*

**pre-calculus**

if i had any idea about these problems i wouldnt ask you in the first place.

*April 22, 2012*

**pre-calculus**

(tan^2x-9)(2cosx+1)=0 Find one period 4cos^2x-4cosx+1=0 find all angles and name 8 angles 7sin^2x-22sinx+3=0 find all angles and name 8 angles 2cos^2x-7cosx=-3 find one period sinx(2sinx+1)=0 find one period

*April 22, 2012*

**pre-calculus**

tanx= -12/5 x in quadrant 2 find; sin2x= cos2x= tan2x=

*April 22, 2012*

**pre-calculus**

cosx= -8/17, 180<x<270 find; sin(x/2) cos(x/2) tan(x/2)

*April 22, 2012*

**physics**

Thank you. It was because of the units my units should have been as g/cm^3, so I got it now. Thank you, I really appreciate it :)

*April 10, 2012*

**physics**

Thank you.I don't know why, but it says the answer is wrong even though i have to answer it as g/cm^3 which would be 960000 g/cm^3 i assume, but even that's wrong! :/ I am really confused I don't know why its wrong.

*April 10, 2012*

**physics**

A U-shaped tube is partly filled with water and partly filled with a liquid that does not mix with water. Both sides of the tube are open to the atmosphere. If h1 = 0.46 m and h2 = 0.25 m, what is the density of the liquid? on the left side of the tube is the liquid h2= 0.25 m...

*April 10, 2012*

**Trig Help Please!!!**

i got that far too but i cant figure out the angle C!!!!

*April 5, 2012*

**Trig Help Please!!!**

Find the indicated angle è. (Use either the Law of Sines or the Law of Cosines, as appropriate. Assume a = 95 and c = 137(angle B=38). Round your answer to two decimal places.)

*April 5, 2012*

**System Analysis**

Suppose you are an analyst developing a new executive information system intended to provide key strategic information from existing corporate databases to senior executives to help in their decision making. What type of metholodogy would you use?

*April 1, 2012*

**Physics**

A small circular object with mass m and radius r has a moment of inertia given by I = cmr2. The object rolls without slipping along the track shown in the figure. The track ends with a ramp of height R = 3.0 m that launches the object vertically. The object starts from a ...

*March 29, 2012*

**Physics please help**

I keep getting 1.079 m, but thats wrong I don't know what I am doing wrong I did as you said h=(4.599)^2/2x9.8 but its wrong! And I got 4.599 from v=sqrt(9.8(9-3)/1.39x0.5)

*March 29, 2012*

**Physics please help**

A small circular object with mass m and radius r has a moment of inertia given by I = cmr2. The object rolls without slipping along the track shown in the figure. The track ends with a ramp of height R = 3.0 m that launches the object vertically. The object starts from a ...

*March 29, 2012*

**English**

Anyone help me with my vocabulary homework?

*March 28, 2012*

**Physics**

To Priyanka ???

*March 28, 2012*

**Physics**

There is a table on top there is a string attached to a pulley and than a block is hanged down,which is also attached to the string!

*March 28, 2012*

**Physics**

A small circular object with mass m and radius r has a moment of inertia given by I = cmr2. The object rolls without slipping along the track shown in the figure. The track ends with a ramp of height R = 3.0 m that launches the object vertically. The object starts from a ...

*March 28, 2012*

**physics**

A small circular object with mass m and radius r has a moment of inertia given by I = cmr2. The object rolls without slipping along the track shown in the figure. The track ends with a ramp of height R = 3.0 m that launches the object vertically. The object starts from a ...

*March 27, 2012*

**Physics**

A playground merry-go-round made in the shape of a solid disk, has a diameter of 2.63 m and a mass of 353.9 kg. Two children, each of mass 30.5 kg, sit on opposite sides at the edge of the platform. Approximate the children as point masses. (a) What torque is required to bring...

*March 25, 2012*

**Physics**

Thank you Damon :)!

*March 25, 2012*

**Physics**

A wheel's uniform angular acceleration is constant. Initially its angular velocity is zero. During the first 1.0 s time interval, it rotates through an angle of 90.0°. (a) Through what angle does it rotate during the next 1.0 s time interval? (b) Through what angle ...

*March 25, 2012*

**physics**

A wheel's uniform angular acceleration is constant. Initially its angular velocity is zero. During the first 1.0 s time interval, it rotates through an angle of 90.0°. (a) Through what angle does it rotate during the next 1.0 s time interval? (b) Through what angle ...

*March 24, 2012*

**Physics**

Thanks :) Damon!

*March 23, 2012*

**Physics**

A child pushes a merry go-round from rest to a final angular speed of 0.6 rev/s with constant angular acceleration. In doing so, the child pushes the merry-go-round 1.8 revolutions. What is the angular acceleration of the merry go-round? rad/s^2 This is how i did this, but its...

*March 23, 2012*

**physics**

You are investing an accident in which a vehicle traveling with a horizontal velocity Vo leaves the top of a cliff of height h, and lands a horizontal distance (x) from the base of the cliff. Prove that the relationship between vo and the other variables is given by the ...

*March 22, 2012*

**English**

No wonder can last more then three days.All good things are three Have similar meaning or contradictory meaning or mean neither the same nor opposite

*March 21, 2012*

**Physics Please help!**

Using the parallel axis theorem, we know that I = I_cm + mr^2, where r is the amount of displacement from the symmetry axis. And we know that for a solid cylinder, I_cm = 1/2(mr^2); Further, for a solid sphere I_cm = 2/5(mr^2) (a) ==> I = 1/2(mr^2) + mr^2 = 3/2(mr^2) = 3/2(...

*March 17, 2012*

**Math**

How can you find a copy of the King of the Ring Worksheet. I lost it and I need a new copy

*March 10, 2012*

**geometry**

Mr. Smith built a fence around a piece of land he wons. The piece of land is 30 yards long and 12 yards wide. How may feet of fencing did Mr. Smith use to build the fence?

*March 5, 2012*

**science**

Are there hydgrogen bonds between water molecules in the liquid phase No, and if there were, the water would just be ice (a solid). Yes, and they are continually breaking and reforming. Yes, but they rarely ocuur. No, otherwise the water molecules would not be able to tumble ...

*March 5, 2012*

**14**

A is the correct answer

*March 4, 2012*

**math**

You have 25-1.5foot fence pieces and 1--1.5foot gate. If you place the fenced zone against a barn of infinite size, what is the maximum possible (rectangular) area in the fenced zone, and how long are the sides?

*March 1, 2012*

**math**

In polk middle school, 45% of the students are 6th graders, 35% of the students are 7th graders and the remainder are 8th graders. Would a circle graph of this data that had 3 sections each with a central of 120% be misleading?

*February 29, 2012*

**physics**

A spring gun (k = 26 N/m) is used to shoot a 56-g ball horizontally. Initially the spring is compressed by 17 cm. The ball loses contact with the spring and leaves the gun when the spring is still compressed by 12 cm. What is the speed of the ball when it hits the ground, 1.3 ...

*February 29, 2012*

**Western Civilization**

How did the intellectual theories of Charles Darwin, Karl Marx, Sigmund Freud and others signal a revolution in modern thought?

*February 23, 2012*

**Chemistry**

An aqueous KNO3 solution is made using 72.5 grams of KNO3 diluted to a total solution volume of 2.00 liters. If the molarity of the solution is .359 M and the molality of the solution is .354, what is the mass percent of the solution?

*February 19, 2012*

**physics**

You want to push a 66-kg box up a 30° ramp. The coefficient of kinetic friction between the ramp and the box is 0.35. With what magnitude force parallel to the ramp should you push on the box so that it moves up the ramp at a constant speed? N

*February 16, 2012*

**Physics**

You want to push a 66-kg box up a 30° ramp. The coefficient of kinetic friction between the ramp and the box is 0.35. With what magnitude force parallel to the ramp should you push on the box so that it moves up the ramp at a constant speed? N

*February 16, 2012*

**Chemistry please help**

Elemental mercury was first discovered when a mercury oxide was decomposed with heat, forming mercury metal and oxygen gas. When a 0.204-g sample of the mercury oxide is heated, 0.189 g of mercury metal remains. a)what is mole ratio of mercury to oxygen in the sample? would it...

*February 15, 2012*

**Math**

if a diameter of a quarter is 25 mm. what is the length of a row of quarters whose total value is $10.00?

*February 14, 2012*

**physics**

suppose a 1.50 kg object is suspended from the end of a silicone band. when the object is pulled down and released, the band vibrates at a frequency of 2.08 s-1. calculate the spring constant of this silicone band including units.

*February 1, 2012*

**Math**

Im stuck plz help If a salesperson earns an annual salary of $ 45,000 plus a 5.5 % commission on his sales,then the equation y = _______________ will express his annual earnings in relation tohis sales x. (a) $45,000+0.055x (b)$45,000 −0.055x (c) 0.055x + $45,000x(d)($45...

*January 30, 2012*

**Social Studies**

In the paragraph it says American ships were stopped not only by the British, but also by the French. During that time, Britain and France were at war. Neither country wanted the other to receive any supplies from the U.S.. So both interfered with the U.S. shipping. The ...

*January 25, 2012*