Thursday

February 26, 2015

February 26, 2015

Total # Posts: 422

**physics **

Because a concave lens cannot form a real image of a real object, it is difficult to measure its focal length precisely. One method uses a second, convex, lens to produce a virtual object for the concave lens. Under the proper conditions, the concave lens will form a real ...
*February 14, 2015*

**physics **

An object is placed in front of a concave mirror, 16.0 cm from the mirror's focal point. The image formed by the mirror is two times farther away from the focal point. Calculate the focal length of the mirror. There are actually two possible image distances di that satisfy...
*February 12, 2015*

**Physics **

A)A very narrow beam of white light is incident at 42.20° onto the top surface of a rectangular block of flint glass 12.6 cm thick. The indices of refraction of the glass for red and violet light are 1.647 and 1.672, respectively. Calculate the dispersion angle (i.e., the ...
*January 23, 2015*

**physics **

Light is incident from air onto a flat transparent slab of material, at an angle of 62.2° with the normal. The reflected ray and the refracted ray are perpendicular to each other. What is the index of refraction of the transparent substance?
*January 20, 2015*

**Physics **

A) On a calm, bright day, you're scuba diving in a deep lake (n = 1.33), 6.00 m away from your sailboat in the horizontal direction. When you are 2.20 m below the surface, the top of the sailboat mast appears to you to be in a direction 36.0° from vertical. Calculate ...
*January 14, 2015*

**Physics **

The flywheel of a steam engine runs with a constant angular speed of 112 rev/ min . When steam is shut off, the friction of the bearings and the air brings the wheel to rest in 2.2 h. What is the magnitude of the constant angular acceleration of the wheel in rev/min^2? Do not ...
*April 2, 2014*

**Physics **

A cyclist starts from rest and pedals such that the wheels of his bike have a constant angular acceleration. After 20.0 s, the wheels have made 219 rev. What is the angular acceleration of the wheels? What is the angular velocity of the wheels after 20.0 s? If the radius of ...
*April 2, 2014*

**physics**

A 1.80-kg block slides down a frictionless ramp.The top of the ramp is h1 = 1.21 m above the ground; the bottom of the ramp is h2 = 0.256 m above the ground. The block leaves the ramp moving horizontally, and lands a horizontal distance $d$ away. Calculate the distance d.
*March 5, 2014*

**physics**

Two blocks, each with a mass m = 0.400 kg, can slide without friction on a horizontal surface. Initially, block 1 is in motion with a speed $v$ = 1.20 m/s; block 2 is at rest. When block 1 collides with block 2, a spring bumper on block 1 is compressed. Maximum compression of ...
*March 5, 2014*

**pysics**

A 33.3- kg block (m1) is on a horizontal surface, connected to a 5.1-kg block (m2) by a massless string. The pulley is massless and frictionless. A force of 220.1 N acts on m1 at an angle of 32.p deg. The coefficient of kinetic friction between m1 and the surface is 0.201. ...
*February 21, 2014*

**chemistry**

An aqueous solution of HCl has a concentration of .160m and a density of 1.0691 g/mL. What is the concentration of HCl as molarity?
*February 20, 2014*

**chemisty**

In Duluth, Mn the average temperature is -13.10 deg C . How much ethonal glycol, C2H6O2, must be dissolved in 1.00 kg of water to make a radiator fluid that wouldn't freeze until the temp reached -20.00 deg C? would my answer be 666.5 g C2H6O2 ?
*February 20, 2014*

**physics**

You exert a larger force on the cart than the cart exerts on you. T/F When you stop pushing, the cart will continue moving at the same speed. T/F While the cart is pushed, it has a constant acceleration. T/F
*February 17, 2014*

**physics**

• If you use a cart with half the mass, you reach _______final speed. • If you use half the force, you reach ______ final speed. • If you push twice as long, you cover _______ distance during pushing. • If you use a cart with half the mass, you cover_______...
*February 17, 2014*

**physics**

Starting from the constant-acceleration kinematic equations, write a formula that gives xf in terms of t, xi, vf, and a.
*January 25, 2014*

**Physics**

A person is standing at the top of a 58.0m tall hill. He stumbles and falls.As he rolls down the hill, magically friction has no effect on him! When he is still 25.0m above the base of the hill determine how fast he is moving.
*December 15, 2013*

**Physical Science**

a
*September 12, 2013*

**Math- Probability**

A committee of five people is to be formed from six lawyers and seven teachers. Find the probability that none are lawyers.
*July 29, 2013*

**math**

thirty animals are to be used in a medical experiment on diet deficiency: 3 male and 7 female rhesus monkeys, 6 male and 8 female dogs. If one animal is selected at random, what is the probability of getting a chimpanzee or a dog?
*July 29, 2013*

**math**

There is a woman that has a 40% chance of being in Casper recently, a 30% chance of being in Denver and a 27% chance that she has been to both. Find the probablility that she has been to Casper if she has been to Denver.
*July 29, 2013*

**math**

There is a woman that has a 40% chance of being in Casper recently, a 30% chance of being in Denver and a 27% chance that she has been to both. Find the probablility that she has been to Casper or Denver recently.
*July 29, 2013*

**Math**

If you are given odds of 3 to 4 in favor of winning a bet, what is the probability of winning the bet?
*July 27, 2013*

**Physics**

F=4000sin(20)= 1368.1 FF= 0.3*4000cos(20)= 1127.6 FR= 4000sin(20) + 0.3*4000cos(20)= 2495.7 So 2495.7 N required to move it up the slope 1127.6 N is required to prevent the load from sliding back
*July 5, 2013*

**Physics**

W=mg= 4000 or do i multiply this by 9.81
*July 5, 2013*

**Physics**

A 4000N block is moved up a slope that is 20 degrees to the horizontal. If the coefficient of friction is 0.3, find the force parallel to the slope to: a) move the load up the slope b) prevent the load from sliding back
*July 5, 2013*

**Algebra**

The graph below shows the expected monthly temperature of a certain city from April to August; the readings that correspond to the vertical lines are taken on the first day of each month. (For example, the expected temperature on April 1 is 70 degrees.)
*June 12, 2013*

**Statistics**

To test H0: = 80 versus H1: < 80. a simple random sample of size n = 22 is obtained from a population that is known to be normally distributed. a) If ¯x = 76.9 and s = 8.5, compute the test statistic.
*April 25, 2013*

**Physics**

Why would normal force be set to zero to calculate the minimum possible speed a rider can have at the top of a loop. Please i need help, this is due in few hours
*April 18, 2013*

**Physics**

A rock dropped into a pond produces a wave that takes 15 s to reach the opposite shore, 35.8 m away. The distance between consecu- tive crests of the wave is 3.3 m. What is the frequency of the wave? Answer in units of Hz
*April 18, 2013*

**chem**

If it takes 84.2 min for the concentration of a reactant to drop to 20.0% of its initial value in a first-order reaction, what is the rate constant for the reaction in the units min-1?
*April 14, 2013*

**physics**

A rocket cruising past earth at 0.800c shoots a bullet out the back door,opposite the rocket's motion,at 0.900c relative to the rocket. What is the bullet's speed relative to the earth?
*April 11, 2013*

**Physics**

How much work is done pushing a wheel barrow full of cement 5.3m forward if a force of 500N is applied 20 degrees from the vertical?
*April 11, 2013*

**Physics**

A stopper tied to the end of a string is swung in a horizontal circle. If a mass of the stopper is 13.0 g, and the string is 93.0 cm, and the stopper revolves at a constant speed 10 times in 11.8 secs, what is the tension on the string? I tried solving this question using the ...
*March 25, 2013*

**Physics help**

A 90 kg parachutist in free fall has an acceleration of 6.8 m/s^2. What is the frictional force provided by air resistance when she is accelerating at this rate? For this question i got 612N but the text book answer says it is 270N. Pls help!! I'm confused
*March 21, 2013*

**Physics**

The amount of internal energy needed to raise the temperature of 0.26 kg of water by 0.3C is 326.5 J. How fast must a 0.26 kg baseball travel in order for its kinetic energy to equal this internal energy? Answer in units of m/s
*March 14, 2013*

**Physics**

A worker drives a 0.460 kg spike into a rail tie with a 2.16 kg sledgehammer. The hammer hits the spike with a speed of 64.5 m/s. If one third of the hammer’s kinetic en- ergy is converted to the internal energy of the hammer and spike, how much does the total internal ...
*March 14, 2013*

**Physics**

What is the final equilibrium temperature when 7 g of milk at 5C is added to 117 g of coffee at 68C? Assume the specific heats of milk and coffee are the same as that of water, and neglect the specific heat of the container. Answer in units of C
*March 13, 2013*

**Physics**

A basketball is thrown from the ground into the air at an angle of 30 degrees to the horizontal. If this object reaches a maximum height of 5.75m, at what velocity was it thrown? How am i suppose to do this question if no velocity is given? I need help. I have a test tomm.
*March 5, 2013*

**Physics**

A basketball is thrown from the ground into the air at an angle of 30 degrees to the horizontal. If this object reaches a maximum height of 5.75m, at what velocity was it thrown? How am i suppose to do this question if no velocity is given? I need help. I have a test tomm.
*March 4, 2013*

**Physics**

A 64.7 kg astronaut is on a space walk away from the shuttle when her tether line breaks. She is able to throw her 14.1 kg oxygen tank away from the shuttle with a speed of 7.45m/s to propel herself back to the shuttle. Assuming that she starts from rest (rela- tive to the ...
*February 26, 2013*

**MATH**

Write the equation of a line perpendicular to the given line but passing through the given point. y=x+4 (-7,1)
*February 18, 2013*

**Physics**

An ore car of mass 37000 kg starts from rest and rolls downhill on tracks from a mine. At the end of the tracks, 9.9 m lower vertically, is a horizontally situated spring with constant 3.9 × 10 5 N/m. The acceleration of gravity is 9.8 m/s 2 . Ignore friction. How much ...
*February 8, 2013*

**Physics**

The force required to stretch a Hooke’s-law spring varies from 0 N to 63.5 N as we stretch the spring by moving one end 5.31 cm from its unstressed position. Find the force constant of the spring. Answer in units of N/m
*February 8, 2013*

**Physics**

A pendulum bob is released from some initial height such that the speed of the bob at the bottom of the swing is 1.5 m/s. The acceleration of gravity is 9.81 m/s 2 . What is the initial height of the bob? Answer in units of m
*February 5, 2013*

**Physics**

An outﬁelder throws a 1.05 kg baseball at a speed of 99 m/s and an initial angle of 47.5 ◦ . What is the kinetic energy of the ball at the highest point of its motion? Answer in units of J
*February 5, 2013*

**Physics**

A 19 g bullet is accelerated in a riﬂe barrel 70.6 cm long to a speed of 506 m/s. Use the work-energy theorem to ﬁnd the average force exerted on the bullet while it is being accelerated. Answer in units of N
*February 5, 2013*

**Calculus and vectors**

Vector AB is a vector whose tail is at (-4,2) and whose head is at (-1,3). Calculate the magnitude of vector AB Determine the coordinates of point D on vector CD, if C (-6,0) and vector CD= vector AB. Please I need some help. Is there a formula to solve this? Pls help
*February 5, 2013*

**Calculus and vectors**

Vector AB is a vector whose tail is at (-4,2) and whose head is at (-1,3). Calculate the magnitude of vector AB Determine the coordinates of point D on vector CD, if C (-6,0) and vector CD= vector AB. Please I need some help. Is there a formula to solve this? Pls help
*February 5, 2013*

**Math**

If Julie needs 3 1/4 cups of oatmeal, how many 1/4 cups oatmeal will shw use?
*January 30, 2013*

**math**

ok i see it thanks
*January 30, 2013*

**math**

Posted by Ted on Wednesday, January 30, 2013 at 5:05pm. susan has $450. she uses 30% of her money to but a dress and 20% of the remainder to buy a pair of shoes. how much money does she have left? i got $225.00 left. am i right math - Ms. Sue, Wednesday, January 30, 2013 at 5:...
*January 30, 2013*

**math**

susan has $450. she uses 30% of her money to but a dress and 20% of the remainder to buy a pair of shoes. how much money does she have left? i got $225.00 left. am i right
*January 30, 2013*

**Religion**

What's a good life in today's society? Some people think a good life is having money, family and friends. I do not know how else to describe what a good life is in TODAY'S SOCIETY
*January 28, 2013*

**Religion**

Hi. How does faith, charity and hope show leadership and service. I know the definitions to these words but i don't get how they connect to leadership and service. Please help
*January 28, 2013*

**math**

Marty ate 1/4 of his pizza and Luis ate 1/3 of his pizza. Marty ate more pizza than Luis. Is that possible? Explain.
*January 26, 2013*

**Chemistry**

Using oxidation numbers, explain why this reaction is not a redox reaction? CaCo3 --------> CaO + Co2 Please help.
*January 26, 2013*

**Math**

Hi. How to you solve 6.3*10^-4=4x^3 on a calculator? What buttons or functions do you press on the calculator to solve this
*January 12, 2013*

**Math**

Hi. How to you solve 6.3*10^-4=4x^3 on a calculator? What buttons or functions do you press on the calculator to solve this
*January 12, 2013*

**English**

I have difficulty restating my thesis in a different way in my conclusion. my thesis: Ruby's sense of responsibility becomes her weaknesses as it makes her blind to the fact that her decision to stay with a man that maltreats her is wrong. For this, she develops a habit of...
*December 19, 2012*

**math**

A group of students have volunteered for the student council car wash. Janet can wash a car in m minutes. Rodrigs can wash a car in m-5 minutes, while Nick needs the same amount of time as Janet.If they all work together, they can wash a car in about 3.23 minutes. How long ...
*December 18, 2012*

**English**

ok thanks.
*December 17, 2012*

**English**

Thanks. I have one more. I have to rephrase the word "moves on" Inspite of her experience with Johnwoodrow, Ruby moves on forgiving him after his death but did not give up her bad habit-smoking.
*December 17, 2012*

**English**

Instead of moving out of the marriage, Ruby thinks the only way to cope with the situation and yet ignore Johnwoodrow is to start smoking and drinking.
*December 17, 2012*

**English**

My teacher wants me to reword"moving out of the" in this sentence ''Instead of moving out of the marriage''. I cant think of anything. pls help
*December 17, 2012*

**religion**

What is the role of the church in relation to media today? How does media affect people morally and ethically? please help
*November 28, 2012*

**physics**

A 2 kg mass falls 40 m and buries itself into the ground 0.40 m. Find: a) How much work was done by gravity, b) How much potential energy was lost, and c) What was its speed when it hit the ground, and d) the average force causing the mass to stop once it hit the ground.
*November 28, 2012*

**chemistry**

I don't know either. I will have to ask my teacher about it. Thanks for helping :)
*November 19, 2012*

**chemistry**

A puncture in the tubing of a refrigerator can cause severe frosbite as chloroethane C2H5Cl, vaporizes. Use this thermochemical equation to calculate the heat absprbed when 23.6g of chloroethane vaporizes at its boiling point (9.66kj) C2H5Cl(liquid) + 26.4kj arrow C2H5Cl(gas).
*November 19, 2012*

**chemistry**

A puncture in the tubing of a refrigerator can cause severe frosbite as chloroethane C2H5Cl, vaporizes. Use this thermochemical equation to calculate the heat absprbed when 23.6g of chloroethane vaporizes at its boiling point (9.66kj) C2H5Cl + 26.4kj arrow C2H5Cl. pls i need ...
*November 19, 2012*

**Algebraic. Expressions**

9/5
*November 15, 2012*

**math**

solve the inequality 3(2x+4)greater than and equal to 2x
*November 12, 2012*

**Physics- Elena please help! I'm so confused!!**

A luggage carousel at an airport has the form of a section of a large cone, steadily rotating about its vertical axis. Its metallic surface slopes downward toward the outside, making an angle of 21.0° with the horizontal. A 37.0 kg piece of luggage is placed on the ...
*October 29, 2012*

**CHEMISTRY**

At what temp do hydrogen molecules, H2, have the same rms speed as nitrogen molecules, N2, at 455 C? At what temperature do hydrogen molecules have the same average kinetic energy?
*October 23, 2012*

**Chemistry**

At what temp do hydrogen molecules, H2, have the same rms speed as nitrogen molecules, N2, at 455 C? At what temperature do hydrogen molecules have the same average kinetic energy?
*October 23, 2012*

**Physics**

A stone is thrown straight up at 8.99 m/s. What is the stone's acceleration in m/s/s at the top of its rise?
*October 4, 2012*

**Physics**

A stone is thrown straight up. To reach a height of 6.49 m above its release point, what must its initial speed be in m/s?
*October 4, 2012*

**Physics**

A soccer player kicks the ball toward a goal that is 29.2 m in front of him. The ball leaves his foot at a speed of 19.1 m/s and an angle of 33.4Â° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not ...
*October 4, 2012*

**Chemistry**

A denaturation/renaturation (similar to the one carried out by Anfinsen with ribonuclease) experiment was carried out using insulin. However, in contrast to Anfinsen's results, only less than 10% of the activity of insulin was recovered when urea and BME were removed by ...
*September 8, 2012*

**math**

what are the intervals to be conidered when finding the solutions in 4/6x-4 - 2/2x+2 please help. i am so lost and confused
*July 24, 2012*

**Calculus**

The area is bounded by y= x^3, x= 2 is rotated around the x-axis. Find the volume using calculus.
*July 24, 2012*

**math**

what if all the values you put in do not work. how would you write the intervals.?
*July 24, 2012*

**math**

thanks so much :)
*July 24, 2012*

**math**

how do you solve this inequality 3x-2 < x+4/x-2 please help i dont get it
*July 24, 2012*

**science -chemistry **

Mr. Currie pours himself some coffee into a paper cup before making his way to the amusement park. The coffee temperature is 350C when the cup is placed on the kitchen counter with room temperature of 20o C. Mr. Currie was called to the phone for last minute arrangements, and ...
*July 23, 2012*

**math grade 12**

its 35° and 20° sorry :$
*July 23, 2012*

**math grade 12**

What is the arc length if the central angle is 225 degrees and the radius of a circle is 3 cm? pls help. i don"t get it
*July 21, 2012*

**math**

solve the inequality 3x-2 < x+4/x-2. please help
*July 21, 2012*

**math grade 12**

i need to know the mathematical model for finding the cooling of a hot liquid. and what the letters mean. pls help thanks
*July 18, 2012*

**math grade 12**

how to solve log basex 8=-1/2 pls help
*July 17, 2012*

**math**

how to solve log basex 8=-1/2 pls help
*July 17, 2012*

**math**

yeah it helped. thanks :)
*July 17, 2012*

**math**

how do you Solve 2log x-log 3=2 pls help
*July 17, 2012*

**math**

how do you create a function that has a graph with the given features: a. A vertical asymptote at x=2; a horizontal asymptote at y=0; no x-intercept; y-intercept is 3
*July 11, 2012*

**math**

how do you create a function that has a graph with the given features: a. A vertical asymptote at x=2; a horizontal asymptote at y=0; no x-intercept; y-intercept is 3 please help.
*July 11, 2012*

**math**

how do you find the domain in 2/x^2+3? pls help
*July 11, 2012*

**math**

how do you find the range of this function X-2/X+2 without using the graph? pls help
*July 10, 2012*

**math**

how do you factor X^3+X^2-9X-9 pls help. I dont know what to do
*July 5, 2012*

**math**

How do you fully factor 8X^3-27. pls help.
*July 5, 2012*

**math**

How do you factor X^3+5x^2-28x-32? pls help
*July 5, 2012*

**math**

How to fully factor X^3-8. pls help
*July 5, 2012*

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