Saturday

February 6, 2016
Total # Posts: 2,643

**physics**

a 4 kg mass is dropped on a spring below. the mass falls 2 meters before stopping and the spring compresses 40 cm in the process. what is the spring constant?
*October 6, 2012*

**physics!!**

An 8.82g bullet is fired into a 235g block that is initially at rest at the edge of a table of h = 1.05 m height (see the figure below). The bullet remains in the block, and after the impact the block lands d = 2.16 m from the bottom of the table. Determine the initial speed ...
*October 6, 2012*

**physics**

A roller-coaster vehicle has a mass of 400 kg when fully loaded with passengers. r1 = 11 m and r2 = 17 m. If the vehicle has a speed of 17 m/s at A, what is the magnitude of the force that the track exerts on the vehicle at this point?
*October 4, 2012*

**physics**

A tire placed on a balancing machine in a service station starts from rest and turns through 4.82 revolutions in 1.48 s before reaching its final angular speed. Calculate its angular acceleration.
*October 4, 2012*

**physics**

A tire placed on a balancing machine in a service station starts from rest and turns through 4.82 revolutions in 1.48 s before reaching its final angular speed. Calculate its angular acceleration.
*October 4, 2012*

**physics**

Which of the following correctly describe the gravitational attraction between Earth and the Moon? -The Earth and the Moon exert equal size gravitational forces on each other. -The gravitational force of the Moon on the Earth is towards the Moon. -Both the Earth and the Moon ...
*October 4, 2012*

**Is this right?**

I think you made a slight error in moving your variables around; the equation should look like this: 6y = 4x - 9 To have the equation in y = mx + b form, you need to make sure there is no coefficient in front of the y variable. To do this, divide both sides by 6: y = (2/3)x...
*October 3, 2012*

**General Chemistry**

What is the velocity of an electron ejected, if any, from a piece of metal whose work function is 2.227 x 10^-19 J when a photon whose wavelength is 319 nm hits the metal in a vacuum? I know the answer is 9.372 x 10^5 m/s, but I am not entirely sure of how to get to this ...
*October 3, 2012*

**math**

With there being 5 shelves in the bookcase and each one taking up an inch of space inside the bookcase, there are 54 inches of space available. (59 - 5 = 54) This number is the amount of available shelf space to put books. With 5 shelves, there are 6 spaces to put books. ...
*October 3, 2012*

**English**

I'm supposed to write a two paragraph anecdote.
*October 1, 2012*

**English**

I need to write an anecdote, and I was wondering if my story of the flight to cancun , if that was an anecdote, or if a day in canada would be an anecdote.
*October 1, 2012*

**English**

Would "the flight to cancun" be an anecdote or a memoir? Would "a day in Canada" be an anecdote or a memoir?
*October 1, 2012*

**physics**

A 29.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 17.00 m. When she is partway down the slide, at a height h2 of 8.00 m, she is moving at a speed of 6.90 m/s. Calculate the mechanical energy lost due to friction
*September 30, 2012*

**College Physics**

If the spring is compressed a distance of 0.150 m and the gun fired vertically as shown, the gun can launch a 27.6g projectile from rest to a maximum height of 16.1 m above the starting point of the projectile. Neglecting all resistive forces, determine the spring constant. ...
*September 30, 2012*

**PHYSICS**

Sue and Jenny kick a soccer ball at exactly the same time. Sues foot exerts a force of 40.6 N to the north. Jennys foot exerts a force of 84.8 N to the east. What is the magnitude of the resultant force on the ball. Answer in units of N. What is the direction Of the resultant ...
*September 30, 2012*

**PHYSICS**

Two lifeguards pull on ropes attached ton a raft. If they pull in the same direction, the raft experiences a net external force of 341 N to the right. If they pull in opposite directions, the raft experiences a net external force of 170 N to the left. Find the magnitude of the...
*September 30, 2012*

**Chemistry**

How many milliliters of a 0.81 M HCl solution are needed to react completely with 2.2 g of zinc to form zinc(II) chloride?
*September 29, 2012*

**Math**

Which one of these five words does not belong and why: Acupuncture Puppet Corpuscle Juniper Repulsion
*September 26, 2012*

**math**

Which one of these five words does not belong and why: Acupuncture Puppet Corpuscle Juniper Repulsion
*September 26, 2012*

**English**

Thank you
*September 25, 2012*

**English**

Which sentence contains a helping verb? A. The group of small children startled the ducklings. B. I walked to the movie theater. C. A small snake slithered across the yard. D. Sophia will be taking swimming lessons for the first time.
*September 25, 2012*

**math**

I disagree with all of you. Oh! Never mind I actually agree with all of you.
*September 24, 2012*

**science**

suspension could be oil on water and a solution could be vinegar
*September 24, 2012*

**dyanmics PLEASE HELP!!!**

This deals with a cam follower. The slotted bar rotates with constant angular velocity, theta=12 rad/s. The follower 'A' follows the circular cam as the bar rotates. The arm is pinned at a distance h=0.2m to the left of the cam's center. The radius of the cam is rc...
*September 23, 2012*

**dyanmics PLEASE HELP!!!**

LOLOLOLOL
*September 23, 2012*

**dyanmics PLEASE HELP!!!**

A carpenter asks his helper to toss an apple to him. The carpenter is 12 ft up and 12 ft to the right of the helper, who throws the apple at Vo=32 ft/s. There are two values of theta that cause that apple to land in the carpenters hand. What are they?
*September 23, 2012*

**dynamics**

A carpenter asks his helper to toss an apple to him. The carpenter is 12 ft up and 12 ft to the right of the helper, who throws the apple at Vo=32 ft/s. There are two values of theta that cause that apple to land in the carpenters hand. What are they?
*September 23, 2012*

**dynamics**

PLEASE HELP!
*September 23, 2012*

**dynamics**

This deals with a cam follower. The slotted bar rotates with constant angular velocity, theta=12 rad/s. The follower 'A' follows the circular cam as the bar rotates. The arm is pinned at a distance h=0.2m to the left of the cam's center. The radius of the cam is rc...
*September 23, 2012*

**US history**

The sedation Act allowed the national government to jail people for
*September 22, 2012*

**Chem**

There are two stable isotopes of Gallium Their masses are 68.92558 and 70.9247050 AMU. If the average atomic mass of gallium is 69.7231, what is the natural abundance of the lighter isotope? I don't know where to start!
*September 20, 2012*

**Chemistry**

AHH they are rounding! I feel silly.
*September 20, 2012*

**Chemistry**

I meant HANDS ---> INCHES --> CM
*September 20, 2012*

**Chemistry**

This is meant to be simple, but for some reason I'm not getting the right answer. Question is: Perhaps the most famous horse race ever in the United States was the 1938 race between two thoroughbreds, War Admiral and Seabiscuit, both of whom stood about 15 hands high. ...
*September 20, 2012*

**arrays**

I think it's 0
*September 20, 2012*

**General Chemistry (Chem101)**

A chemist mixes two liquids A and B to form a homogeneous mixture. The densities of the liquids are 2.0514 g/mL for A and 2.6678 g/mL for B. When she drops a small object into the mixture, she finds that the object becomes suspended in the liquid; that is, it neither sinks nor...
*September 20, 2012*

**Physics**

A bullet of 10g enters a target at 100 ms-1 and leaves it 0.01 s later. Calculate: i. The rate of change of momentum of the bullet ii. The resistance offered by the target iii. The loss of kinetic energy of the bullet iv. The deceleration of the bullet v. The distance ...
*September 19, 2012*

**algebra 2**

solve for x: (exact answers) 5^(2x+1)-26(5^x)+5=0
*September 19, 2012*

**algebra 2**

list all solutions if x^(4)+x^(3)-11x^(2)+9x+20=0 and if one of the roots is x=2-i
*September 19, 2012*

**geometry**

if the length of each edge in a cube is increased by the same percent and the result was a cube that had 25% more volume than it originally had, by what percentage were the edges increased
*September 19, 2012*

**Physics**

A bullet of 10g enters a target at 100 ms-1 and leaves it 0.01 s later. Calculate: i. The rate of change of momentum of the bullet ii. The resistance offered by the target iii. The loss of kinetic energy of the bullet iv. The deceleration of the bullet v. The distance ...
*September 19, 2012*

**geometry**

EARTH COMPLETES ONE FULL ROTATION EACH DAY MAKING THE SUN APPEAR TO RISE AND SET. IF THE SUN PASSES DIRECTLY OVER HEAD, BY HOW MANY DEGREES DOES ITS POSITION IN THE SKY CHANGE EVERY HOUR?
*September 19, 2012*

**english **

Which sentence BEST combines the ideas shown below? (I put an arrow on the one I think the answer is) --->A.The football player did not seem seriously injured. As a precaution, the trainers moved him carefully. B.The football player did not seem seriously injured, and as a...
*September 18, 2012*

**Algebra**

4/3x -1
*September 18, 2012*

**Algebra**

Find an equation for the line satisfying the given conditions.Through (3, 3) and parallel to 4x - 3y = 6. y=?
*September 18, 2012*

**11th grade maths**

How do you fiind the averege rate change
*September 17, 2012*

**pre - algebra**

maria had $123 she spent $35,loaned $20 to a friend and recieved her $90 paycheck how much does she have now? so you would do 123 -20=103 and then 103 - 20=83 and 83 + 90 =wich is 173 so that would be the answer right?
*September 16, 2012*

**pre-algebra**

and then like um my next question is maria had $123 she spent $35,loaned $20 to a friend and recieved her $90 paycheck how much does she have now? so you would do 123 -20=103 and then 103 - 20=83 and 83 + 90 =wich is 173 so that would be the answer right?
*September 16, 2012*

**pre-algebra**

so the 15 - 9=4 okay thanks ms. sue for helping me with my 7th grade pre algebra hw I will probably need more help I will jut post my other questions too.
*September 16, 2012*

**pre-algebra**

A football team gained 4 yd, lost 2 yd, gained 11yd, lost 8 yd, and then lost 9 yd. Find the net gain or loss.
*September 16, 2012*

**physics**

A bicycle has a speed of 7.5m/s at 4.3sec and a constant acceleration of 2.6m/s^2. the bicycle is at the origin (on the positive x-axis) when 1.2sec. How far from the origin is the bike at 7sec? Answer in units of m
*September 16, 2012*

**physics**

A bicycle has a speed of 7.5m/s at 4.3sec and a constant acceleration of 2.6m/s^2. the bicycle is at the origin (on the positive x-axis) when 1.2sec. How far from the origin is the bike at 7sec? Answer in units of m
*September 16, 2012*

**Physics**

In deep space (no gravity), the bolt (arrow) of a crossbow accelerates at 187m/s^2 and attains a speed of 114m/s when it leaves the bow. For how long is it accelerated? Answer in units of m/s What speed will the bolt have attained 2.8 sec after leaving the crossbow? Answer in ...
*September 16, 2012*

**physics**

A body moving with uniform acceleration has a velocity of 11.1cm/s when it's coordinate is 3.59cm. If it's x coordinate 2.48sec later is -3.58cm, what is the x-component of it's acceleration. Answer in units of cm/s^2
*September 16, 2012*

**Algebra 2**

How many 2 liter mountain dew bottles would it take to fill up the earth if the radius is 6378.1?
*September 15, 2012*

**Physics**

A partly-full paint can has 0.83 U.S. gallons of paint left in it. (a) What is the volume of the paint, in cubic meters? (b) If all the remaining paint is used to coat a wall evenly (wall area = 12 m2), how thick is the layer of wet paint? Give your answer in meters.
*September 14, 2012*

**science**

the ph of a 0.280m solution of a weak base. B has been measured ph --8.69. using this information. calculate the base ionisationconstant kbof b
*September 14, 2012*

**math**

Find all the values of x in the interval [0,2π] that satisfy the equation: 8sin(2x)=8cos(x)
*September 13, 2012*

**7th Grade Science**

Autotrophic, Multicellular, Eukaryote, Vascular/Non-Vascular, Cell Wall, Photosynthesis, and Needs Water To Survive.
*September 13, 2012*

**Algebra II**

9x+y is less than or equal to 1700 9x+3y is less than or equal to 1800 4x+8y is less than or equal to 2400 ***I need help plugging in numbers for x and y. The numbers don't have to be the same for each question.
*September 13, 2012*

**Math**

Solve for t using natural logarithms. 7e^3t = 10e^2t
*September 11, 2012*

**Math**

The quantity demanded each month of Russo Expresso Makers is 250 when the unit price is $136.oo. The quantity demanded each month is 1,2oo when the unit price is $98.00. The suppliers will market 700 espresso makers if the unit price is $58.00 or lower. At a unit price of $74....
*September 11, 2012*

**Physics**

A ping pong ball is rolling across a table at 22 cm/s. When the ball is 78 m away from the edge your little brother starts to blow on it. If the little doofus hopes to prevent the ball from falling off the edge, what minimum acceleration must be achieved?
*September 10, 2012*

**xx**

explain problem: 3.1 - 2.076=
*September 10, 2012*

**Finite, Math, Probability**

Assume that there are 17 board members: 9 females, and 8 males including Carl. There are 4 tasks to be assigned. What is the probability that at least one female and Carl are assigned tasks?
*September 10, 2012*

**Chemistry**

Help with any of these: 21. Aluminium sulphate is often used by gardeners to acidify soil and can be produced by the reaction 2Al(OH)3(aq) + 3 H2SO4(aq) à Al2(SO4)3(aq) + 6 H2O(l) The volume of 0.275 mol/L H2SO4(aq) needed to react completely with 112...
*September 9, 2012*

**Physics**

An attacker at the base of a castle wall 3.82 m high throws a rock straight up with speed 7.10 m/s from a height of 1.45 m above the ground. (a) Will the rock reach the top of the wall? __yes __no (b) If so, what is its speed at the top? If not, what initial speed must it have...
*September 8, 2012*

**Help On Math**

Thanks
*September 8, 2012*

**Help On Math**

A movie theater has fixed costs of $5,500 per day and variable costs averaging $2 per customer. The theater charges $7 per ticket. How many customers per day does the theater need in order to make a profit? Give the smallest possible value. The theater makes a profit when it ...
*September 8, 2012*

**phys**

A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.30 m/s. The car is a distance d away. The bear is 32.9 m behind the tourist and running at 4.92 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
*September 6, 2012*

**phys**

A pellet gun is fired straight downward from the edge of a cliff that is 28.5 m above the ground. The pellet strikes the ground with a speed of 26.1 m/s. How far above the cliff edge would the pellet have gone had the gun been fired straight upward?
*September 6, 2012*

**phys**

A woman on a bridge 84.7 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 8.02 m more to travel before passing under the bridge. The stone hits the water 4.86 ...
*September 6, 2012*

**Math**

I need to solve this set of differential equations {y'+(t/2)1, y(0)=1} and then find the limiting value as t approaches infinity. I'm not sure where to start. I found the answer to the differential equation to be: y(t)=e^-t^2/4[e^(r^2/4)dr +Ce^(-t^2/4)where the [ sign ...
*September 6, 2012*

**physics**

A heavy piece of equipment(85kg) is being moved by elevator between floors in a building. Two identical small cranes are used. A cable connecting each crane to a mounting hook on the top of the piece of equipment.The cable from one crane is at an angle of 22 degree below the ...
*September 5, 2012*

**DT**

For my DT homework I need to do a health and safety poster on a Pillar Drill. I need to find health and safety facts on a Pillar Drill. Please can you help me. Thanks
*September 4, 2012*

**physics**

You are driving down the road at a constant speed. another car going a bit faster catches up with you and passes you. draw a position graph for both vehicles on the same set of axes and note the point on the graph where the other vehicles passes you. if you have been passed by...
*September 4, 2012*

**physics**

A viking sails from his home port and travels east at 15km/hr.after 10 hours, the wind change and he is blown south west at 20km/hr for six hours.at his point wind drops, the ship is becalmed and doesnot move for the next ten hours.becoming tired of waiting,the viking order ...
*September 4, 2012*

**physics**

A landing craft of mass 12000 kg prepare itself for moon landing. when at a vertical distance 160m above the moons surface its downward velocity is 15 m/s. a retrorocket is fired to give the craft an upward thrust to slow its speed to zero as it meet the surface.calculate the ...
*September 4, 2012*

**science**

A simple model for a person running a 100m race is to assume the sprinter runs with constant acceleration until reaching top speed, and then maintains that speed through the finish line. If a sprinter reaches their top speed of 11.2ms-1 in 2.15s, what will be their total time?
*September 4, 2012*

**chemistry**

Sulfuric acid (H2SO4) is prepared commercially from elemental sulfur using the contact process. In a typical sequence of reactions, the sulfur is ﬁrst burned: S + O2 → SO2 , then it is converted to SO3 using a catalyst: 2 SO2 + O2 → 2 SO3 . The resulting SO3...
*September 2, 2012*

**chemistry**

A 12.8 g sample of iron ore is treated as follows. The iron in the sample is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 21.3 g. What was the mass of iron in the sample of ore? Answer in units of g
*September 2, 2012*

**algebra**

how do i explain how to write 20 miles/4 hours as a unit rate?
*August 30, 2012*

**ap chemistry**

name five organic compounds that melt between -40 degrees and -49 degrees celsius
*August 26, 2012*

**Algebra**

Thank You Reiny i see what you did there :) i was confused on some of the things but i understand how to do that stuff now! Thanks Again!, Emily
*August 22, 2012*

**Algebra**

BTW!!! I need it explained on like how you figured it out because i have another ? like it and i want to try and do that one on my own!!! THX! ;)
*August 22, 2012*

**Algebra**

I need help with this like really badly sooo yeahhhh:) here it is: Hugo withdrew some money from his bank account. He spent one third of the money for gasoline. Then he spent half of what was left for a haircut. He bought lunch for $6.55. When he got home,he had $13.45 left. ...
*August 22, 2012*

**health**

Teachers are there to help, not provide answers to kids. She's handing them the necessary tools to get the answer and they are still choosing to be lazy and guess. Stop judging a teacher for being impatient. Blame a parent for not disciplining their child
*August 14, 2012*

**Physics**

20/9
*August 7, 2012*

**health!**

the answer is C
*August 3, 2012*

**programming**

Given a = 5, b=1, x=10, and y =5, create aprogram that outputs the result of the formula f = (a b)(x y) using a single printf() function. B> Create a program that uses the same formula above to output the result; this time however, prompt the user for the values a, b, x, ...
*July 24, 2012*

**Math **

1.) A security code has seven characters. Each code begins with two digits, then two letters, and finally three digits. the number of distinct security codes possible if repetition is allowed? 2.) How many ten digit phone numbers are possible if a number may not begin with a 0...
*July 16, 2012*

**Physics**

For part c, it says regarding the common velocity Vf isn't that different than Vcm?
*July 10, 2012*

**Physics**

I figured out a and b, but I can't seem to figure out C.
*July 10, 2012*

**Physics**

Car 1 has a mass of m1 = 65 103 kg and moves at a velocity of v01 = +0.76 m/s. Car 2, with a mass of m2 = 92 103 kg and a velocity of v02 = +1.5 m/s, overtakes car 1 and couples to it. Neglect the effects of friction in your answer. (a) Determine the velocity of their center ...
*July 10, 2012*

**Physics**

Two forces, 1 and 2, act on the 5.00 kg block shown in the drawing. The magnitudes of the forces are F1 = 58.0 N and F2 = 26.5 N. What is the horizontal acceleration (magnitude and direction) of the block?
*June 27, 2012*

**Physics**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end...
*June 27, 2012*

**Physics**

In the amusement park ride known as Magic Mountain Superman, powerful magnets accelerate a car and its riders from rest to 36 m/s (around 80 mi/h) in a time of 5.5 s. The mass of the car and riders is 4900 kg. Find the average net force exerted on the car and riders by the ...
*June 26, 2012*

**Physics**

A person with a black belt in karate has a fist that has a mass of 0.70 kg. Starting from rest, this fist attains a velocity of 6.9 m/s in 0.15 s. What is the magnitude of the average net force applied to the fist to achieve this level of performance?
*June 26, 2012*

**Physics**

Could someone explain how to do this?
*June 22, 2012*