Wednesday

April 16, 2014

April 16, 2014

Total # Posts: 275

**physics**

A 50kg girl sits at the top of a slide 6m long tilted at an angle of 30 degrees. if it takes her 3.3s to slide to the bottom and the coefficient of kinetic friction is 0.45, how fast will she be going at the bottom?

**physics**

57m

**physics**

A car has a flywheel ( a diks of R=0.2m and uniformly distributed mass M=100kg) that can convert 25% of the rotational kinetic energy into translational kinetic energy. The mass of the car is 1000kg ( including flywheel). Suppose the car is at rest, and the flywheel has a angu...

**physics**

Hi, Elena. Thanks for helping me with the neutron star problem. I knew the formula, but kept getting answers that were not close to the possible choices. What variables did you use. Thanks again for your help.

**physics**

Assume that the mass of a neutron star is 1.5 times that of the Sun and the radius of the neutron star is 10 km. Ignore effects of Special Relativity. What is the approximate speed at which an object released from far away (at zero speed) reaches the surface of a neutron star?...

**PHYSICS URGENT HELP **

a charges electric potential energy within an electric field is calculated as the product of the ____ of it's position times the magnitude of it's charge

**Physics**

ANY ANSWERS WILL HELP! THANKS! 1. Isolated points of electric charge are called ____. 4b. ____ was the American physicist who first measured this fundamental unit of charge. 5. This type of electrification occurs when the charging rod touches an electroscope. 6. This type of e...

**chemistry**

determine the density in copper at 1305K. 1 mole of vacancies in copper is 104kJ. The answer I calculated this time is 8.4572*10^22. I am not sure if this correct. Thanks.

**chemistry**

DDD I may not be using the right formula. I am getting negative answers. Down to last chance.

**Chemistry**

I posted a question earlier today to determine the vacancy density in copper. The formation of 1 mole in Cu is 104kJ. Temperature is 1305K. My result is -2.19*10^-22. This does not look right to me. Any ideas. Thanks.

**chemistry**

I have been having a problem with solving a chemistry problem. The problem requires finding the density in copper at 1305K (the temperature changes when you reset the problem). I think I am using the proper formula, (N_v/N_s=Ae^-changeH_v/kT). My results are a very large numbe...

**chemistry**

I have been having a problem with solving a chemistry problem. The problem requires finding the density in copper at 1305K (the temperature changes when you reset the problem). I think I am using the proper formula, (N_v/N_s=Ae^-changeH_v/kT). My results are a very large numbe...

**biology**

Small gene big plasmid Question 2 Part E wrong. Question 2 Part F Determine the DNA sequence of PCR products. I do not understand how to handle this problem. On home works they were wrong and the solutions were confusing. Please give me a clue.

**chemistry**

N_v/N_s =Ae ^-change Hv/kT. What is the value of e^? Thanks.

**Physics **

6) The relationship between force and acceleration is given by Newton’s 2nd Law: Fnet = ma. In this case this becomes: Fapp...

**Chemistry**

Determine the sulfate ion concentrate in a solution prepared by diluting 15.00 ml of 0.115 M Y2(so4)3 with 35 ml of water?

**physics **

a baseball was launched from 1.5 m above the ground. the ball was caught at a position 4.5m above the ground with a speed of 28m/s moving at a angle of 30 degrees below horizontal: find initial velocity - time of flight - range

**physics **

a baseball was launched from 1.5 m above the ground. the ball was caught at a position 4.5m above the ground with a speed of 28m/s moving at a angle of 30 degrees below horizontal: find initial velocity - time of flight - range

**physics **

a baseball was launched from 1.5 m above the ground. the ball was caught at a position 4.5m above the ground with a speed of 28m/s moving at a angle of 30 degrees below horizontal: find initial velocity - time of flight - range

**STATISTICS**

Should be C

**Physics**

When switched off, a spinning ceiling fan slows down with an angular acceleration of 1.2 rad/s2. If the fan was spinning at the rate of 10π rad/sec before it was turned off, how many revolutions did it go through before coming to the stop?

**Math**

There are 100 runners, each given a distinct bib labeled 1 to 100. What is the most number of runners that we could arrange in a circle, such that the product of the numbers on the bibs of any 2 neighboring runners, is less than 1000?

**Physics**

One of the proposed mechanisms for the lift of an aircraft is the pressure difference that develops due to the aerodynamic shape of the wings. Higher pressure develops bellow the airplane which lifts it up. Suppose you have a semi-circular wings with radius 1 m. If air molecul...

**MATH**

6+(4X7/14-1)=7

**Algebra**

Joe put 1/2 of his allowance into a savings. He spent 2/5 of the remainder on game rentals and 3.75 on snacks. How much is monthly allowance?

**Math**

If you have 1/2cup of water and you take out 3/8 of water how much do you have left

**math**

yes. there are a total of 10. thanks for the help

**math**

some years in the 20th century have 4 different odd digits. How many of those years have the sum of the digits greater than 20?

**Physics**

It seems wrong, please help!

**Physics**

Please help anyone!

**AP Chem**

MnS(s) + 2 H+ --> Mn2+ + H2S(g) At 25 C the solubility product constant, Ksp, for MnS is 5 x 10-15 and the acid dissociation constants K1 and K2 for H2S are 1 x 10-7 and 1 x 10-13, respectively. What is the equilibrium constant for the reaction represented by the equation ...

**physics**

A coin is placed on an old record turntable which rotates at 78 rpm. The coefficient of friction between the record and the coin is 0.17. b) At what distance (m) from the center will the coin begin to slide off the record? c) What is the period of the rotation (s) of the penny?

**physics**

A toy plane of mass 0.624 kg is flown in a circle when attached to a string. The plane moves around the circle with a rotational speed of 8.09 rpm. The length of the string is 2.60 m. What is the tension in the string?

**physics**

A student puts on a Dresden Dolls disc in her cd player which spins at 1800 revolutions per minute. A compact disc has a mass of about 0.016 kg and a radius of 6.0 cm. a) What is the period of rotation in seconds? b) What is the frequency of the rotating disc? d) What is the l...

**physics**

c) A penny sits 12 cm from the center of a record turning at 33 1/3 rpm. What is the tangential speed in m/s?

**physics**

On August 12, 2005 the Mars Reconnaissance Orbiter (MRO) was launched from Earth and reached Mars on March 10, 2006. The orbiter is in roughly circular orbit about 390 km above the martian surface. Mars has a radius of 3396 km and a mass of 0.642 x 1024 kg (6.42E23 kg). Here a...

**applied math**

At 1.25 per square foot what is tjh cost of cleaning a rug with dimension 9 ft.3 in.by 6feet 9 in,?

**math**

rewrite each expression using the distrubitive property 6x + (-5x)

**math**

I have 92 quarters, 46 dimes and 23 nickels in my jar. how money do i have

** 6th grade math**

what is 13/16 minus 1/4?

**History**

2. The 1978 Supreme Court decision in Bakke v. Regents of the University of California A. established the rights of students to appeal college admissions policies. B. established the "red state-blue state" divide. C. ruled in favor of...

**TRIG**

Given that tan¤=3/4 and ¤ is in the second quadrant find sin2¤ (¤=theta)

**TRIG**

Given that tan¤=3/4 and ¤ is in the second quadrant find sin2¤ (¤=theta)

**Physics**

A2.0-kg piece of steel with a temperature of 70 degree C is submerged in 1.0 kg of water at 15 degree C. At what temperature does the water/metal system reach equilibrium? The specific heat of steel is 0.107 cal/(g*K). Specific Heat of water is 4185 J/(kg*K.( The answer is 27 ...

**Physics**

7. A plastic cup, 15.0 cm in height, is filled to the rim with water. A small hole is punctured in the cup at a height 9.00 cm above the bottom of the cup and is allowing water to spew out. At what distance does the water land from the bottom of the cup?(Answer is 14.6 cm)

**Physics**

small cube of copper (density = 8930 kg/m3) is used to support a large cube of marble (density = 2560 kg/m3). The copper cube has sides of length 2.00 cm and is carefully placed on a flat, level table under the center of the cube of marble that has sides of length 30.0 cm. Gi...

**calculus**

lim_(theta->0)(cos(6 theta)tan(6 theta))/(theta)

**Algebra**

Thanks!

**Algebra**

The car traveling 100 mph states from a complete stop

**Algebra**

Leaves 2 minutes after the car at 80 mph passes it

**Algebra**

How long does it take a care traveling 100 mph to catch up to a car traveling 80 mph

**Math**

The price of a camera increased from $75 to $90 find the percent of the increase price

**Chemistry-Help**

The pressure of gas is measured at 550 mm Hg. How do you calculate this to Torr, lb/in2, atm, and in Hg? Please show conversions so that I can understand? Thank you!

**integral calculus**

a rectangular plate 12ft long and 8 ft wide is submerged vertically with the longer edge in the surface of the water. Find the force on one side of the plate.

** math**

Jon and Remy were in a car race. When Jon finished the race in 45min, Remy had only driven 2/3 of the distance. Remy's average speed for the race was 50m/min less than Jon's. a) Find the distance of the race. b) What was Remy's speed?

**chem**

Aspartame, an amide, is the sweetener commonly used in diet cola.What is the carboxylic acid that is a reactant in the production of aspartame.

**chem**

carbamic acid and ammonia react to form an amide and water. What is the amide product of this reaction.

**math**

Thank you, Steve!

**math**

The ratio of A's stickers to B's stickers was 3:4. After A bought another 18 stickers and B lost 10 stickers, the ratio became 3:2. Find the number of stickers both of them had at first.

**math**

Observe the patterns in the sequence below. What is the missing algebraic expression in the box? Express your answer in terms of c. 5 4 5a 2a 10b b 40 2 6 ? 2 5c

**math**

Class A has the same number of students as Class B. The ratio of the number of girls in Class A to the number of girls in Class B is 3 : 2. The ratio of the number of boys in Class A to the number of boys in Class B is 3 : 5. What is the ratio of the number of girls to boys in...

**math**

Shop A sold a notebook for $1200. This was 125% of the price of a similar notebook sold in Shop B. Find the price of the notebook in Shop B. During a sale, both shops gave the same percentage of discount. Dennis bought the notebook from Shop B and found that she paid $175.20 l...

**math**

Thank you, Steve.

**math**

Thank you, Steve.

**math**

Sasa had some 20-cent and 50-cent coins. 7/8 of the coins were 20-cent coins and the rest were 50-cent coins.After Sasa had spent $72.50 worth of 50-cent coins and 5/7 of the 20-cent coins, she had 2/7 of the coins left. Find the total amount of money Sasa left.

**chem**

Predict out of which of the following would a dialysis bag be permeable to? Potassium Ions= DNA= Sucrose= No? Starch =No? Sulfate Ion=yes Chloride Ion=yes Protein=No I'm not sure about potassium ions or DNA though.

**math**

Thank you, Steve! Appreciate your help.

**math**

May and Bill took 49 hours to complete their History project. They worked separately on their own project. If May had worked 5 hours less and Bill had worked 6 hours more, May would have put in 2 hours more than Bill. How many hours did May put in for the History project?

**math**

Thanks a lot Steve!

**math**

Mrs Sim spent some money on 45 buns. She spent the same amount of money on 20 muffins. Each muffin cost $0.95 more than each bun. How much did she spent altogether?

**Calc.**

1000 yds of fence x 1000-x 1. Show that the area function to be maximized is A(x) = ( pi + 4 / 16pi) x^2-125x+62500 2. Show that the critical point of A(x) is x=1000pi/pi+4 3. 1000yds of fencing and y>2r, find the values of r and y that maximizes the area of this new region...

**SOCIAL STUDIES**

HOW OLD IS THE GREAT BARRIER REEF?

**Social Studies**

Where is the great barrier reef?

**Social Studies**

How old is the great barrier reef?

**Social Studies**

How big is the great barrier reef?

**Social Studies**

What other information about the Great barrier reef people would like to know about it?

**Social Studies**

Why do people visit the great barrier reef?

**Social Studies**

How was the great barrier reef made or built?

**Social Studies**

Is the great barrier reef natural or man-made?

**math**

5 4 5a 2a 10b b 40 2 6 ? 2 5c What is the missing algebraic expression? Express your answer in terms of c.

**math**

5 4 5a 2a 10b b 40 2 6 ? 2 5c What is the missing algebraic expression?

**math**

5 4 10b b 6 ? 5a 2a 40 2 2 5c The above numbers are presented in 3 sets of 4 boxes each. What is the missing algebraic expression in the box in the last set?

**english**

Its actually Asteroids.....I just took the test and Mexico was wrong.

**calculus**

67

**Algebra**

If A=(x-y)-z and B=x-(y-z), then A-B= what?

**grade 10 chemistry**

factor labels 200ml per hour to kl per year

**COMM215**

Should I use a comma after story and after the question mark as shown below? “Have you ever read the story, ‘The Tell-Tale Heart’ by Edgar Allan Poe?,” Dave asked. And, should I use a comma after say and after the question as shown below? “Did the prof...

**COMM215**

Many thanks Ms. Sue and Writeacher. I would appreciate your opinion about the corrections below. Regarding question #8 we can't alter anything on the exam, our material does nto say anything about the use of ?!?. #36 just to be sure and do not take the risk of using "...

**COMM215**

Many thanks Ms. Sue and Writeacher. I would appreciate your opinion about the corrections below. Regarding question #8 we can't alter anything on the exam, our material does nto say anything about the use of ?!?. #36 just to be sure and do not take the risk of using "...

**COMM215**

Can you tell me if everything is correct? Final Grammar Test Part I: True or False 1. The following word group is a FRAGMENT: That movie, one of my favorites. _X_True __False 2. The following word group is a FRAGMENT: The local baseball team, needing a good pitcher most of all...

**geometry**

Find the value of x When one angle is 67 degrees and The lenthb of the triangle is 21

**algebra**

Janelle has $ 20 and is saving $ 6 per week. April has $ 150 and spending $ 4 per week , when will they both have the same amount of money ? i know by trial and error i will get 13 weeks, but how do i solve it by algebra ? please

**income tax**

How much approximately would I pay in income tax in canada on $500,000.00 on stock profit in one year. I will have no other expenses to declare

**MATH**

what is the unknown standard deviation of this problem Ho: m=4.7 Ha: m<4.7 alpha 1% standard deviation: unknown after a random sample of 36 the mean is 4.5 with s=0.42

**Physics**

B. During the collision. One-hundredth of a second after, the balls velocity would surpass equilibrium, and move towards the perceived negative quantity.

**statistics**

Multiplicaiton Rule: P(math and computer)=P(math) *P(computer) P(math and computer) = 72/650 * 105/650 = 0.018 The probability that a student enrolled at this college is a math and biology major is 0.018

**physics**

It takes 175 kJ of work to accelerate a car from 23.9 m/s to 27.7 m/s. What is the car's mass?

**physics**

a car starts from rest and accelerates at in a straight line at a constant rate of 4.5m/s/s. How far will the car travel in 35 seconds.

**Algebra**

what is the square root of 5 divided by 2 times the square root of 125?

**Chemistry question Please help**

Consider the expected conductivities of CaCl2(aq) and Ca(OH)2(aq). Which of these can be expected to have the higher conductivity. Explain your reasoning.