Tuesday

June 30, 2015

June 30, 2015

Total # Posts: 3,028

**Physics**

An open railroad car of mass 2445 kg is coasting with an initial speed of 22 m/s on a frictionless, horizontal track. It is raining, and water begins to accumulate in the car. After some time, it is found that the speed of the car is only 5 m/s. How much water (in kilograms) ...
*May 30, 2012*

**Physics**

A car engine is initially rotating at 180 rad/s. It is then turned off and takes 1.20 s to come to a complete stop. What is the angular acceleration of the engine? Assume acceleration is constant.
*May 30, 2012*

**Physics**

An electric motor is rated to have a maximum power output of 0.72 hp. If this motor is being used to lift a crate of mass 188 kg, how fast (i.e., at what speed) can it lift the crate? Hint: Assume the only other force on the crate is the force of gravity.
*May 28, 2012*

**American History**

I think maybe Progressives believed that direct election of senators gave more control of government to the people?
*May 27, 2012*

**American History**

One more question: Why did the Progressive movement want the direct election of senators? Senators elected indirectly made little effort to represent the people. Progressives believed that having representatives elected by state legislatures was sufficient. Progressives ...
*May 27, 2012*

**American History**

What was one reform the Progressive movement achieved? direct election of U.S. senators reduction of government regulation religious involvement in government elimination of prohibition
*May 27, 2012*

**physics!**

while running a marathon, alex is producing about 900 calories per hour. 1 calorie is 4184 j. if the specific heat of the human body is 3500 j/kg x c, how many degrees celsius would alexs temperature increase if he did not sweat and ran the marathon in 3 h and 10 min? he has a...
*May 22, 2012*

**Physics**

A car of mass 1670 kg is traveling without slipping on a flat, curved road with a radius of curvature of 34 m. If the car's speed is 14 m/s, what is the frictional force between the road and the tires?
*May 21, 2012*

**Physics**

A car of mass 1670 kg is traveling without slipping on a flat, curved road with a radius of curvature of 34 m. If the car's speed is 14 m/s, what is the frictional force between the road and the tires?
*May 20, 2012*

**Physics**

Thank you so much!
*May 20, 2012*

**Physics**

A compact disc spins at 2.8 revolutions per second. An ant is walking on the CD and finds that it just begins to slide off the CD when it reaches a point 3.2 cm from the CD's center. What is the coefficient of friction between the ant and the CD?
*May 20, 2012*

**Physics**

Thank you!
*May 16, 2012*

**Physics**

There are two forces acting on an object. One force has a magnitude of 39 N and is directed along the +x axis. The other force has a magnitude of 25 N and is directed along the +y axis. What is the direction of the acceleration of the object? Express your answer by giving the ...
*May 16, 2012*

**Physics**

That makes a lot more sense now. Thanks!
*May 16, 2012*

**Physics**

A sled is pulled with a horizontal force of 17 N along a level trail, and the acceleration is found to be 0.40 m/s2. An extra mass m = 4.4 kg is placed on the sled. If the same force is just barely able to keep the sled moving, what is the coefficient of kinetic friction ...
*May 16, 2012*

**Physics**

A horizontal rifle is fired at a target 47 m away. The bullet falls vertically a distance of 8 cm on the way to the target. (a) What is the speed of the bullet just after it left the rifle? (b) What is the speed of the bullet just before it hits the target?
*May 16, 2012*

**Physics**

You work for a moving company and are given the job of pulling two large boxes of mass m1 = 115 kg and m2 = 286 kg using ropes as shown in the figure below. You pull very hard, and the boxes are accelerating with a = 0.21 m/s2. What is the tension in each rope? Assume there is...
*May 15, 2012*

**Physics**

A crate is placed on an inclined board as shown in the figure below. One end of the board is hinged so that the angle θ is adjustable. If the coefficient of static friction between the crate and the board is μS = 0.37, what is the value of θ at which the crate ...
*May 15, 2012*

**Physics**

You work for a moving company and are given the job of pulling two large boxes of mass m1 = 115 kg and m2 = 286 kg using ropes as shown in the figure below. You pull very hard, and the boxes are accelerating with a = 0.21 m/s2. What is the tension in each rope? Assume there is...
*May 15, 2012*

**algebra 1**

simplify and show work 3+4-10 dived by 2
*May 15, 2012*

**Math**

a right angle because 190 degree is a right triangle so find the coralation and simplify awnser determine value and round to the nearest tenth degree
*May 15, 2012*

**Physics**

Nevermind I figured it out.
*May 14, 2012*

**Physics**

A squirrel is resting in a tall tree when it slips from a branch that is 40 m above the ground. It is a very agile squirrel and manages to land safely on another branch after only 0.71 s. What is the height of the branch it lands on?
*May 14, 2012*

**Physics**

A car is moving with a velocity of 16 m/s when the brakes are applied and the wheels lock (stop spinning). The car then slides to a stop in 37 m. Find the coefficient of kinetic friction between the tires and the road.
*May 14, 2012*

**Physics**

A person is pushing on a refrigerator that sits on a level floor. Use Newton's third law along with his second law to find the magnitude of the acceleration of a man as he pushes the refrigerator. Assume the man has a mass of 62 kg, he exerts a force of 128 N, the ...
*May 14, 2012*

**algebra**

Grace runs 3 miles per day. Find this rate in feet per day
*May 8, 2012*

**Chemistry - please help!**

thank you!
*May 8, 2012*

**Chemistry - please help!**

The decomposition of KClO3 produces oxygen gas and solid KCl. What mass of KClO3 must be decomposed to produce 126 L of oxygen gas at 133 Celsius and .88 atm? I know I need to use PV=nRT but I can't figure out how.
*May 8, 2012*

**math**

A 20 feet vertical pole cast a shadow of 32 feet. What is the angle of elevation of the sun?
*May 7, 2012*

**Algebra 2**

Simplify (3^−2 − 2^−2)^−1 The answer is -36/5 I just need to know how to do it.
*May 2, 2012*

**Algebra 2**

What are the x-intercepts of the circle with center (0, −2) and radius 3?
*May 1, 2012*

**Algebra 2**

A baseball player swings and hits a pop fly straight up in the air to the catcher. The height of the baseball in meters t seconds after it is hit is given by a quadratic function h(t) = −5t^2 + 10t + 1. What is the maximum height of the baseball?
*May 1, 2012*

**Algebra 2**

How much of a 60% orange juice drink must be mixed with 30 gallons of a 10% orange juice drink to obtain a mixture that is 50% orange juice.
*May 1, 2012*

**consuer math**

Question 1: The cost of joining a gym is $195 plus $50 per month. Rewrite the equation to express cost as a function of time, identify the slope and the y-intercept.
*April 27, 2012*

**consumer math**

The cost of joining a gym is $195 plus $50 per month. Rewrite the equation to express cost as a function of time, identify the slope and the y-intercept.
*April 27, 2012*

**math**

Tommy has right rectangular prism with base length 5 and a cylinder with radius 2.5. If both objects have equal surface areas, what is : a)the height of the right rectangular prism? b) the height of the cylinder? Use Pi =3.14
*April 25, 2012*

**history**

one of president nixons goals was to reduce the number of nuclear weapons the united states had
*April 24, 2012*

**Physics**

A 1.55 kg mass attached to a spring oscillates with a period of 0.375 s and an amplitude of 16.5 cm. (a) Find the total mechanical energy of the system. (b) Find the maximum speed of the mass.
*April 24, 2012*

**Physics**

.819 s
*April 24, 2012*

**Physics**

A uniform rectangular sign of width 47.6 cm, height 25.0 cm, and negligible thickness hangs vertically from supporting hinges attached at its upper edge. Find the period of small-amplitude oscillations of the sign.
*April 23, 2012*

**Physics**

A uniform rectangular sign of width 47.6 cm, height 25.0 cm, and negligible thickness hangs vertically from supporting hinges attached at its upper edge. Find the period of small-amplitude oscillations of the sign.
*April 23, 2012*

**Physics**

Find the length of a simple pendulum that completes 17.0 oscillations in 35.0 s.
*April 23, 2012*

**Physics**

A 1.55 kg mass attached to a spring oscillates with a period of 0.375 s and an amplitude of 16.5 cm. Find the total mechanical energy of the system Find the maximum speed of the mass
*April 23, 2012*

**Physics**

A 1.55 kg mass attached to a spring oscillates with a period of 0.375 s and an amplitude of 16.5 cm. Find the total mechanical energy of the system Find the maximum speed of the mass
*April 22, 2012*

**Physics**

Radio waves are electromagnetic waves that travel at a speed of 3.00 108 m/s, the speed of light. An AM radio station has an assigned frequency of 1350 kHz, which means that the radio waves broadcast by the station are at this frequency. Find the wavelength of these radio waves.
*April 22, 2012*

**Physics**

The free-fall acceleration at the surface of planet 1 is 18 m/s^2. The radius and the mass of planet 2 are twice those of planet 1. What is the free-fall acceleration on planet 2?
*April 21, 2012*

**Trig**

Dalco manufacturing estimate that its weakly profit, P, in hundreds of dollars,can be approximated by the formula P= -4x²+8x+7, where x is the number of units produced per week, in thousands. 1)How many units should the company produce per week to earn maximum profit 2)...
*April 21, 2012*

**Physics**

A certain radio station broadcasts at 1430 kilohertz. This is the frequency of oscillation of electrons in the transmitting antenna producing the radio wave. Find the period of the electrons' motion.
*April 20, 2012*

**Social Studies**

Why were Hoosiers divided over the issues of slavery and loyalty before the Civil War?
*April 19, 2012*

**calculus**

Two consecutive days of the week experience a maximum temperature of 90 degrees F at 1:00pm and a minimum temperature of 44 degrees F at 1:00am. Write a cosine equation measured in house that would model this behavior. Let x=0 represent 1:00pm on the first day.
*April 18, 2012*

**Physics**

James Joule once attempted to measure the increase in temperature of the water in a waterfall resulting from its decrease in gravitational potential energy. How high would the waterfall have to be for the temperature at the bottom to be 1°C higher than at the top?
*April 17, 2012*

**Physics**

James Joule once attempted to measure the increase in temperature of the water in a waterfall resulting from its decrease in gravitational potential energy. How high would the waterfall have to be for the temperature at the bottom to be 1°C higher than at the top?
*April 17, 2012*

**Physics**

How much heat is required to raise by 10.30°C the temperature of 1.2 kg of water? How much heat is required to raise by 10.30°C the temperature of 1.2 kg of iron?
*April 16, 2012*

**Physics**

A car of mass 1.25 103 kg is initially moving on a level road at a speed of 17.0 m/s. Compute the increase in temperature of the brakes, assuming that all the mechanical energy ends up as internal energy in the brake system. Assume a total heat capacity of 10,000 J/C°.
*April 16, 2012*

**physics**

Ice of mass 11.0 kg at 0.00° C is placed in an ice chest. The ice chest has 3.00 cm thick walls of thermal conductivity 1.00 10-5 kcal/s · m · C° and a surface area of 1.25 m2. (a) How much heat must be absorbed by the ice before it melts? (b) If the ...
*April 16, 2012*

**Calculus**

Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. (Round your answer to four significant digits.) HINT [See Quick Example page 532.] Enclosed ...
*April 13, 2012*

**Investment**

f you invest $25,000 at 8% interest compounded continuously, what is the average amount in your account over one year?
*April 12, 2012*

**Calculus**

Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. Between y = −x and y = x/2 for x in [0, 6]
*April 12, 2012*

**Physics**

What is the speed of a wave whose frequency is 9.00Hz and wavelength is 0.654m?
*April 12, 2012*

**social studies**

how did geography affect europeans in latin america?
*April 12, 2012*

**Calculus grade 12**

a)3cos*2x
*April 12, 2012*

**Chemistry**

The pressure of an unknown gas is measured with a manometer. Instead of mercury the manometer is filled with a liquid (X) whose density is 0.553 g/cc. The pressure is measured as 653 mmX. What is the pressure in mmHg?
*April 11, 2012*

**s.s help**

Growing there own if i was ona farm id wanna grow my own way much cheaper
*April 11, 2012*

**math**

if you tossed two number cubes, what sum has the greatest probability of occuring? Explain.
*April 11, 2012*

**Chemistry**

Given 3.90mL of 1.80M HCl diluted to .520L, whats the pH?
*April 5, 2012*

**Chemistry**

Given 3.90mL of 1.80M HCl diluted to .520L, whats the pH?
*April 5, 2012*

**math**

A basketball team needs 5 players. The team can choose from a group of 7 players. Explain how to find the number of combinations of players that can be on the team.
*April 4, 2012*

**Human resources**

Role Play In this mock executive team meeting, you will assume the role and responsibility for a specific function (for example, human resources, marketing, finance, legal, and operations). The team will be given a scenario in which strategic decisions are to be made for rapid...
*April 4, 2012*

**Chemistry**

How much ice in grams would have to melt to lower the temperature of 58.2 g of water from 55.0 degrees C to 0 degrees C? Assume the density of water is 1.0 g/mL Any advice on how to tackle this problem would be appreciated. Thanks
*April 3, 2012*

**statistics**

how do you find the quartile Q3 of the list of 24 sorted values: 30,33,35,38,40,46,46,47,47,49,50,51,53,53,54,56,60,65,73,74,77,78. what is the formuala and how do you work it?
*April 3, 2012*

**chemistry**

If you add 5.0 mL of 0.50 M HCl solution to 20.0 mL to Buffer C, what is the pH of the buffer? (where buffer C is 8.203 g sodium acetate with 100.0 mL of 1.0 M acetic acid)
*March 31, 2012*

**Physics **

A girl of mass 55 kg throws a ball of mass 0.8 kg against a wall. The ball strikes the wall horizontally with a speed of 25 m/s, and it bounces back with the same speed. The ball is in contact with the wall 0.05 s. What is the average force exerted on the wall by the ball? A) ...
*March 30, 2012*

**Biology**

do all specific proteins have the same function in different living organisms?
*March 28, 2012*

**chemistry**

given the equilibrium constant for the following reaction at 500 K, 2 NO (g) + O2 (g) <==> 2 NO2 (g) Kc = 6.2x10^5 calculate the equilibrium constant for the reaction expressed as partial pressures, Kp. the answer is 1.51x10^4. How do i get this?
*March 28, 2012*

**chemistry**

Why do the concentrations of Pb 2+ and SO4 2- ions in a saturated solution of PbSO4 in contact with solid PbSO4 remain the same when the solution evaporates to half of its original volume? it has to do with equilibrium.
*March 28, 2012*

**chemistry**

For the gaseous equilibrium represented below, it is observed that greater amounts of PCl3 and Cl2 are produced as the temperature is increased. PCl5 (g) <==> PCl3 (g) + Cl2 (g) a) what is the sign of delta S for the reaction? Provide a legitimate rationale for the ...
*March 28, 2012*

**ap chemistry**

When 50.0 mL of a 0.010 M CuNO3 solution is mixed with 150.0 mL of a 0.010 M NaCl solution, a precipitate forms (Ksp = 1.9 x 10^-7). a) Determine all final ion concentrations b) Determine the mass of the precipitate formed. How do i do this?
*March 28, 2012*

**Math**

Suppose that 600 meters of fencing are used to enclose a corral in the shape of a rectangle on three sides, and then a semicircle on the fourth side (The diameter of the semicircle is equal to the width of the rectangle). Find the dimensions of the corral with maximum area.
*March 28, 2012*

**math**

Sorry. n=3/2 or 1.5
*March 28, 2012*

**math**

n= 2/3
*March 28, 2012*

**math **

2/3 x n = 4/9
*March 28, 2012*

**Physics**

An indestructible bullet 1.85 cm long is fired straight through a board that is 11.5 cm thick. The bullet strikes the board with a speed of 400 m/s and emerges with a speed of 285 m/s. (a) What is the average acceleration of the bullet as it passes through the board? Give your...
*March 28, 2012*

**Physics**

Find the angular velocity of a clock's second hand and the linear speed and linear acceleration of a point on the second hand 1.96 cm from the rotation axis.
*March 26, 2012*

**Physics**

Find the angular velocity of a clock's second hand and the linear speed and linear acceleration of a point on the second hand 1.96 cm from the rotation axis.
*March 26, 2012*

**math**

1/2 x 2/3
*March 26, 2012*

**Physics**

2700
*March 25, 2012*

**Integrals/Related Rates(?)/Volume**

Fluid is flowing in a tube that has a radius of 3 centimeters. Water is flowing through a circular cross section at a rate of (9-r^2) cm/s, where r is the distance from the center of the cross section. What is the total amount of water that flows through the cross section in 4...
*March 22, 2012*

**Math**

First, make sure to convert all of your units to meters. Then, sum the sides (so 2*1.4*1.5, two because there are two of the same side, and then do the same for the other two types of sides.
*March 22, 2012*

**Chemistry**

the reaction 2 NO + O2 <=> 2 NO2 (delta H = -114.2 kJ) has a Kc=7.00 x 10^7 at 200 degrees Celsius. what is the value of Kc at 400 degrees celsius? a. 1.25x10^4 b. 1.68x10^8 c.3.91x10^11 d. 5.74x10^22 e. answer not given
*March 20, 2012*

**Chemistry**

what is the solubility in mol/L of insoluble Ca3(PO4)2 (Ksp=1.00x10^-26)in a solution containing .00100 M Na3PO4? a. 2.15x10^-7 b. 7.18x10^-8 c. 7.18x10^-9 d. 1.00x10^-23 e. answer not given
*March 20, 2012*

**humanities**

for my homework my teacher has set me whats the meaning of a human honey pot and i cant find any good websites so i was wondering if you new any
*March 18, 2012*

**Physics**

If a lever is 6 feet long and the fulcrum is six inches from a 500 N boulder, how many newtons of force would be needed to life the boulder?
*March 17, 2012*

**Physics**

all I know is that it's not simply n(wavelength)=dsin(theta) because I plugged the numbers in and they were wrong. (n=1)
*March 17, 2012*

**Physics**

Suppose that a 14-m tall platform has a ramp that is 98 m long. If a box needs 245 N of force of lift it, how many N of force is required to push it up the ramp?
*March 16, 2012*

**Algebra 1**

Factor completely 4x^3+x^2y-36x-9y
*March 15, 2012*

**geometry**

Thank You!! Is there any way you can explain a little bit to me how this answer is found? Thank You soo much for your help it is very greatly appreaciated!!
*March 14, 2012*

**geometry**

Robert is making a scale drawing of a painting that is 48in. wide by 120in. high. His paper is 12in. wide and 24in. tall. He decides to use the scale 1in.= 4in. Is this a reasonable scale?
*March 14, 2012*

**3rd grade math**

What is the difference between the perimeter and the area of a polygon?
*March 13, 2012*

**Chemistry**

Assume you begin with 60 g of water at 20 oC and 60 g of water at 80 oC. After adding the two portions of water into your calorimeter, you determine the temperature of the mixed portions of water to be 45 oC. What is the heat capacity of the calorimeter?
*March 12, 2012*

**organic chemistry**

How many steric interactions are there in CIS-1,3-dimethylcyclohexane? Which groups participate in the interactions and whats the total number of interactions of this type??? Also, if i have the steric strain value for one 1,3 H-CH3 interaction, how can i determine the ...
*March 12, 2012*