Monday

March 30, 2015

March 30, 2015

Total # Posts: 1,954

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...
*March 28, 2015*

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...
*March 28, 2015*

**Chemistry**

A woman expends 96 kJ of energy in walking a kilometer. The energy is supplied by the metabolic breakdown of food intake and has a 35 % efficiency. If the woman drives a car over the same distance, how much energy is used if the car gets 8.7 km per liter of gasoline? The ...
*March 27, 2015*

**math**

The coordinates of (triangle) ABC are A(-3,-1 ) , B( 5,1 ) and C (2,4) (i) Calculate the length of AB , BC and AC (ii) Hence, show that (triangle) is a right- angled triangle
*March 27, 2015*

**chemistry**

50.0 mL of an unknown HCl solution was titrated with 0.449 M NaOH. To reach the equivalence point, 38.4 mL of the NaOH was used. What was the concentration of the HCl?
*March 25, 2015*

**Chem**

0 = [4440g*0.803*(Tf-98.8)] + [2.00*4.186*(Tf-24.8)] Tf = 98.6C
*March 24, 2015*

**Chem **

A 4.44 kg piece of granite with a specific heat of 0.803 J g-1 °C-1 and a temperature of 98.8°C is placed into 2.00 L of water at 24.8°C. When the granite and water come to the same temperature, what will the temperature be?
*March 24, 2015*

**Physics**

lol yoooo you in brahmia's physics class bruh pay attention in class yo
*March 23, 2015*

**Physics**

Can someone walk me through how to solve this? Any help is much appreciated! Two masses moving along a straight line undergo a front-to-back collision. The masses are m1= 60.0 kg, with initial velocity v1 = 17.0 m/s, and m2 = 26.0 kg, with initial velocity v2 = 7.0 m/s. After ...
*March 22, 2015*

**Medical physics**

A silver cube (density of silver is 10 g/cm3) with side length of 3 cm weighs more than an aluminium cube (density of aluminium is 2.96 g/cm3) with side length of 4 cm. The cubes are each suspended by a string and allowed to be completely immersed in two identical jars ...
*March 21, 2015*

**Physics**

It's 0%, I've done the exact same question, I think there's a typo.
*March 18, 2015*

**Physics**

A block of mass 13.9 kg slides from rest down a frictionless 40.0° incline and is stopped by a strong spring with a spring constant 32.3 kN/m (note the unit). The block slides 7.80 m from the point of release to the point where it comes to rest against the spring. When the...
*March 17, 2015*

**Physics**

A M2= 6.40 kg mass is released from rest at height h = 6.60 m . Using the law of conservation of energy, determine the speed of the M1= 2.70 kg mass just as the M2= 6.40 kg mass hits the ground.
*March 17, 2015*

**college algebra**

How much should be deposited in an account paying 3.5% interest, compounded quarterly, in order to have a balance of $ 6,000after 17years and 3months?
*March 14, 2015*

**math**

A cube with length 4cm is divided into 8 identical cubes.How much greater is the combined surface area of the 8 smaller cubes than the surface area of the original cube?
*March 10, 2015*

**math**

A rectangle measuring 7cm by 4cm is enlarged by a ratio of 2:1.what is the area of the enlarged rectangle.
*March 5, 2015*

**Physics**

Can someone help me solve this one? I've tried it a few times, but I don't think I'm getting it right. A block of mass M = 2.2 kg starts from rest at a height of 3.6 m on a fixed inclined plane. The coefficient of kinetic friction between the block and the incline ...
*March 3, 2015*

**Physics**

Can someone walk me through how to work this? It's worded weirdly and I'm not sure how to solve it. Mass M1= 2.2 kg lies on a frictionless table, pulled by another mass M2= 4.1 kg under the in of Earth's gravity. a) What is in N the net force acting on the system ...
*March 3, 2015*

**Physics**

Can someone walk me through how to work this? A block is being pushed up a frictionless incline by an applied horizontal force, F=12.7N. (The angle is θ = 23.80° and the mass is 1.70kg. a) How many forces are acting on the block? b) How many of those forces are along ...
*March 3, 2015*

**Physics**

Can someone help me with this problem? It requires a lot of visualizing and I've never been great at problems like that. A pair of blocks of mass m1 =29.0 kg, and m2 =58.0 kg, are being pushed on a horizontal surface by a constant forces of magnitude F=87.0 N. The angle &#...
*February 28, 2015*

**Physics**

I think I've found everything but e. Here is my work a) acceleration = v-u/t a = 1.95/1.22 a = 1.6 b) 2, gravity and the normal force c) F = m(g – a) F= 42(10-1.6) F = 352.8 d) acceleration = v-u/t a= 1.95/7.8 a= .25 F= m(g-a) F= 42(10-.25) F= 409.5 Does anyone else ...
*February 28, 2015*

**Physics**

A 42 kg man stands on a bathroom scale in an elevator. Starting from rest at the bottom floor, the elevator ascends, attaining its maximum speed of 1.95 m/s in 1.22 s. It travels with this constant speed for the next 7.80 s. The elevator then slows down for 2.20 s and comes ...
*February 28, 2015*

**Physics**

Hey, I'm studying for my physics class, and I'm not sure how to solve this problem. Can someone walk me through it please? I'd really appreciate any help! John throws a baseball from the edge of a cliff with an initial velocity of 17.0 m/s at an angle 27.0° ...
*February 28, 2015*

**math **

If Owen gives $40 to Charley, the will have an equal amount of money. If Charley gives $80 to Owen, the ratio of Owen's money to Charley's money will be 4-1.How much money does Owen have in the beginning? Work: I don't have much but X=Owen C=charley X=C-40 4C=O+80
*February 26, 2015*

**Chemistry**

An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% Carbon and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of -5.20 ...
*February 24, 2015*

**Math**

What is the domain of x/(x-1)? Is it all x <> 1?
*February 23, 2015*

**Physics**

This one has been confusing me, can someone walk me through it? I'd like to know which formulas I need to use and everything. A 121.0 -kg crate is sitting at rest on a ramp leading to the back of a truck. a) How many forces are acting on the crate while it is at rest? b) ...
*February 22, 2015*

**Physics**

Hey! I've tried using equations such as weight=m*g for this problem, but I don't think I'm doing it right. Can someone help? A helicopter was seen carrying a heavy bag of sand (1210.0 kg). A student figured that the acceleration of the sand bag then was 1.4 m/s2 in...
*February 22, 2015*

**Biology**

explain the consequence of x chromosome inactivation in terms of the proteins encoded by the x chromosome genes?
*February 19, 2015*

**Algebra 2**

Describe an infinite geometric series with a beginning value of 2 that converges to 10. What are the first 4 terms of the series?
*February 19, 2015*

**Dynamics**

The 25-lbf block has an initial speed for v0 = 10 ft/s when it is midway between springs A and B. The coefficient of static and kinetic friction between the plane and the block are μs = 0.45 and μk = 0.4, respectively. After striking spring B, the block rebounds and ...
*February 19, 2015*

**Microcomputer applications**

thank you
*February 13, 2015*

**Microcomputer applications**

Do you know if there is an online tutorial for the book Office 2013 Marquee by Rutosky, Sequin, Roggenkamp, Rutosky
*February 13, 2015*

**chem**

nevermind i got it, accidentally put in 5.86 instead of 5.96 :)
*February 8, 2015*

**chem**

Calculate the energy of a photon of green light with a frequency of 5.96 ✕ 10^14 s−1 I keep getting 3.88e-21, but the quiz keeps saying I'm wrong...
*February 8, 2015*

**accounts**

On January 1, 2012, the organizers of the Parsons Corporation obtained their charter and issued 10,000 shares of $1 par common stock for $4 per share. During 2012, the corporation earned $30,000 in cash revenue and paid $20,000 in cash expenses, not including income tax. The ...
*February 6, 2015*

**Probability**

Alfred and Bob toss a coin alternatively, and whoever gets a head first will win. They play many times and whoever loses in the previous play will toss first at the next play. If Eric tosses first at the first play, then what is the probability that Eric will win at the 6th play?
*February 6, 2015*

**physics**

A jet plane lands in an airport with a speed of 125 m/s and can accelerate uniformly at a maximum rate of -9.8 m/s2 as it comes to rest. What should be the minimum length of the runway so that the jet plane can land in the airport safely?
*January 30, 2015*

**Physics**

A 7.1 kg watermelon is placed at one end of a 5.9 m, 244 N scaﬀolding supported by two cables. One supporting cable is at the opposite end of the scaﬀolding, and the other is 0.54 m from the watermelon. How much tension is in the cable at the end of the sca&#...
*January 28, 2015*

**chem**

1. A 4.61 g sample of one of the substances listed in the table below was heated from 21.3°C to 315.7°C, requiring 190 J to do so. What substance was heated? I got mercury(l) 2. Calculate the energy required in joules and calories to heat 33.9 g of aluminum from 30.7&...
*January 27, 2015*

**Chemistry re-post**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M TI3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...
*January 19, 2015*

**Chemistry (Electrochemistry)**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M Ti3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...
*January 19, 2015*

**Chemistry**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M Ti3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...
*January 18, 2015*

**Chemistry (Re-post)**

The distribution co-efficient of butanoic acid (pKa = 4.8) between water and two organic solvents are given below; Benzene D= 3.0 Octanol D= 6.2 a) which organic solvent is expected to extract the acid most efficiently from the water? explain your answer. So you expect that ...
*January 17, 2015*

**Chemistry**

The distribution co-efficient of butanoic acid (pKa = 4.8) between water and two organic solvents are given below; Benzene D= 3.0 Octanol D= 6.2 a) which organic solvent is expected to extract the acid most efficiently from the water? explain your answer. I understand that D ...
*January 17, 2015*

**Chemistry**

Imagine that you have a 7.00L gas tank and a 4.00L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 145atm , to what pressure should you fill the...
*January 15, 2015*

**Chemistry (Electrochemistry)**

The thickness of a pure Ag plate on a base metal is to be determined by controlled potential coulometry. The metal sheet is masked except for a circular area, 0.5cm in diameter. Electrical connection is made to the metal and the sheet is clamped in a cell so that the unmasked ...
*January 10, 2015*

**geometry **

From an apartment window 24 m above the ground, the angle of depression of the base of a nearby building is 38 degrees and the angle of elevation is of the top is 63 degrees. How tall is the nearby building?
*January 5, 2015*

**Math**

6 9/8-25/6=
*December 23, 2014*

**AP Calc**

For the curve f(x)=x ln x+(1-x)ln(1-x), find the value of x in the interval 0<x<1 where f(x) has a minimum.
*December 20, 2014*

**algebra**

Traveling downstream a certain boat went 21 mph. Traveling upstream it went only 5 mph. Find the speed of the boat in still water and the speed of the current.
*December 18, 2014*

**Chemistry**

If 25.00 ml of H2SO4 solution is titrated to an end point with 32.16 ml of 0.1986 M NaOH, what is the molarity(M) of the H2SO4 acid?
*December 14, 2014*

**Chemistry**

Which of the following factors affect the solubitity? a)temperature of the solutions b)polarity of the solvent vs solute molecules c)partial pressure of the gas above the solution d) all of the above
*December 14, 2014*

**Math**

A boy is dividing M&Ms between himself and his sister. He gives 2 to his sister and takes 2 for himself. He gives 2 to his sister and takes 4 for himself. He gives 2 to his sister and takes 6 for himself, and so on. (b) After n rounds, how many M&Ms does his sister have and ...
*December 12, 2014*

**Physics**

A ball of mass m is attached to a spring with a spring constant k. The system is attached to a thin vertical axis as shown in Figure 4. In its equilibrium vertical position the spring length is L. The axis starts to rotate with a constant angular frequency ω. Find the ...
*December 9, 2014*

**AMA**

A force of 1.24 N pushes against an object with a mass of 0.16 kg for 3.00 min. The object does not move. What is the work done on the object by the force?
*December 8, 2014*

**Math**

Limit(7x+6x^2) / (7x^2+6x) x->inf
*December 8, 2014*

**Sociology**

Alright. Thanks Writeacher.
*December 6, 2014*

**Sociology**

Are Ethnic Groups the same as Societies?
*December 6, 2014*

**history **

the huguenots were
*December 2, 2014*

**Math PLEASE HELP ME**

Thank You reiny do you think you can explan this one The total income from three investments was $2400. After 14 years, Investment I income has doubled, Investment II income has increased by 50% and Investment III went broke. If the income increase in Investment I equals the ...
*November 30, 2014*

**Math PLEASE HELP ME**

A man has $210,000 invested in three properties. One earns 12%, one 10% and one 8%. His annual income from the properties is $20,100 and the amount invested at 8% is twice that invested at 12%. How much is invested in each property? at 12% 10% and 8% What is the annual income ...
*November 30, 2014*

**Math PLEASE HELP ME**

A man has $210,000 invested in three properties. One earns 12%, one 10% and one 8%. His annual income from the properties is $20,100 and the amount invested at 8% is twice that invested at 12%. How much is invested in each property? at 12% 10% and 8% What is the annual income ...
*November 30, 2014*

**Calculus**

The slope of the line tangent to the curve xy+(y+1)^2=6 at the point (2, 1) is
*November 30, 2014*

**math**

The 3rd term of a geometric progression is nine times the 1st term.if the 2nd term is one twenty fourth the 5th term.find the 4th term.(there is a mistake in the 2nd to the last statement.help locate the mistake{final answer 4th term =48).i solved to this extent.ar^2=9 r=3.
*November 28, 2014*

**math**

the 3rd term of a geometric progression is nine times the 1st term.if the 2nd term is one-twenty fourth the 5th term.find the 4th term.(my solution so far).ar^2=9a r=sqr of 9 r=3.help me find the 1st term
*November 28, 2014*

**math**

The 3rd term of a geometric progression is nine times the first term.if the second term is one-twenty fourth the 5th term.find the 4th term. solution ar^2=9a r=sqr of 9 r=3.pls help me on how to get the first term(a)
*November 27, 2014*

**math**

The third term of a geometric progressiom is nine times the first term.if the second term is one-twenty fourth the fifth term.find the fourth term.ar^2=9a. r=sqr of 9 r=3.pls teach me how to get the first term and i can get the 4th term myself
*November 27, 2014*

**Chemistry**

Provide the name(s) for the branched constitutional isomer(s) with the molecular formula C7H16 that have three methyl groups.
*November 24, 2014*

**Chemistry**

Provide the name(s) for the branched constitutional isomer(s) with the molecular formula C7H16 that have three methyl groups.
*November 24, 2014*

**Math**

A stone was dropped off a cliff and hit the ground with a speed of 112 ft/s. What is the height of the cliff? (Use 32 ft/s2 for the acceleration due to gravity.)
*November 20, 2014*

**Math**

A particle is moving with the given data. Find the position of the particle. v(t) = 1.5sqrt(t), s(9) = 33
*November 20, 2014*

**geography**

How has Mexico's culture been shaped by conflict among different people?
*November 20, 2014*

**chemistry**

3. After removing membranes from an eggshell, the shell is dried and its mass is recorded as 5.613 g. The egg is transferred to a 250 mL beaker and dissolved in 25 mL of 6 M HCL. After filtering, the solution containing the dissolved eggshell is diluted to 250 mL in a ...
*November 18, 2014*

**science**

A 2000kg car traveling at a speed of 27m/s skids to a halt on wet concrete where μk = 0.20.
*November 17, 2014*

**Science, Chemistry**

Write reactions showing how each of the following buffers would neutralize added HCl. HF and NaF Express your answer as a balanced chemical equation. Identify all of the phases in your answer. HC2H3O2 and KC2H3O2 Express your answer as a balanced chemical equation. Identify ...
*November 16, 2014*

**Science, Chemistry**

Write neutralization reactions for each of the following acids and bases. HNO3(aq) and Ba(OH)2(aq) Express your answer as a balanced chemical equation. Identify all of the phases in your answer.
*November 16, 2014*

**accounting**

a 10 year coupon bond that yield 5% is issued with a 1000 par value. what is the issuance price of the bond
*November 13, 2014*

**Math**

Question: Write a word problem using 7 groups. And then solve the problem Can you give an example?
*November 12, 2014*

**Physics**

1800n
*November 9, 2014*

**Physics**

A cannon is fired from the ground at an angle of 30 degrees. It is being shot an an initial velocity of 200m/s. What is the maximum height of the cannon ball? How fat will the cannon ball travel before it hits the ground
*November 7, 2014*

**science, chemistry**

Answers please
*November 5, 2014*

**Computing- Python (simple-ish stuff)**

Great thanks so much!
*November 5, 2014*

**Computing- Python (simple-ish stuff)**

Hi, I'm working on this piece of code: numLaptops = 7 laptopCost = 599.50 price = numLaptops * laptopCost print("Total cost of laptops: $%.2f" % price) But the question wants me to explain teh output if I put 2.5 instead of .2, 8.2 instead of it and 3.1 instead ...
*November 5, 2014*

**chem**

Calculate the total pressure in the flask after all of the oxygen has been removed from the air in the flask. Assume that the temperature is 25¡ÆC, the initial barometric pressure is 760 torr and that air is 21% oxygen by volume.
*November 4, 2014*

**chemistry**

A chemist wants to make 5.50 L of a 0.300 M lithium phosphate solution. What mass of lithium phosphate must be used to make this solution?
*November 3, 2014*

**statistics**

Suppose that the amount of time it takes the IRS to refund to taxpayers is normally distributed with a mean of 12 weeks and a variance of 9. a. What percent of taxpayers should get a refund within 5 weeks? b. What percent of taxpayers will get their refund within 10-15 weeks? ...
*October 28, 2014*

**research methods grant writing**

The table labeled “Brooklyn Precinct Activity Measures” shows counts of different indicators from the June 1999 Compstat report. All data are totals for the period January 1, 1999, through June 20, 1999. Notice, in the key to this table, that some indicators are ...
*October 28, 2014*

**calculus**

A lamp post 3m high is 6m from a wall. A 2m man tall is walking directly from the post toward at 2.5m/s. How fast is his 1.5 from the wall
*October 20, 2014*

**mathematics**

what is algerdra
*October 17, 2014*

**chemistry**

a sample of freon-12 occupies 25.5 litters at 28 celsius find its volume at 15 degree celcius when the pressure is kept constant
*October 16, 2014*

**physics**

A water balloon is launched at a building 24m away with an initial velocity of 18 m/s at an angle of 50° above the horizontal. If the balloon misses or shoots over the building, how far will the balloon land from its launch location?
*October 13, 2014*

**physics**

A water balloon is launched at a building 24m away with an initial velocity of 18 m/s at an angle of 50° above the horizontal. At what height will the balloon strike the building?
*October 13, 2014*

**Cheeeem**

how to calculate the weight of solute req'd to prepare 1 liter of 1 normal of: a.) LiOH b.) phosphoric acid HELP.
*October 12, 2014*

**Physics**

A plane starts from rest at the end of a runway and requires 200.0 km/h for takeoff . If it takes 30.0 a to reach takeoff speed, what acceleration must the plane's engines provide to get off the runway ?
*October 7, 2014*

**CALCULOUS**

A bank account is growing by 4.3 % per year. Find the doubling time. Round your answer to the nearest integer. Can someone explain how to solve this step by step. I have been stuck on this for quite a while
*October 3, 2014*

**Pre Calc**

Use the Rule of 70 to estimate how long it takes a dollar-sign 7000 investment to double if it grows at the annual rate 7 %. Compare with the actual doubling times. Round your answers to three decimal places. I found the estimated doubling time using Rule of 70 to be 10. I am ...
*October 3, 2014*

**us history**

These committees act as study groups for the House and Senate. (1 point) select committees conference committees joint committees standing committees
*September 27, 2014*

**Math**

Using the following cash flows for projects A and B, use payback period, discounted payback period, NPV, IRR, and MIRR to see if these are good projects or not. > Project A: (283,000); 46,000; 89,000; 104,000; 123,000; 187,000; and 72,000 > Project B: (318,000); 72,000; ...
*September 27, 2014*

**Engineering Dynamics**

A ball is thrown so that the motion is defined by the equations x=5t and y=2+6t-4.9t^2, where x and y are expressed in meters and t is expressed in seconds. a) find velocity at t=1s, b) find the horizontal distance the ball travels before hitting the ground.
*September 25, 2014*

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