Monday

July 28, 2014

July 28, 2014

Total # Posts: 131

**Physics**

A 74.2-kg climber is scaling the vertical wall of a mountain. His safety rope is made of a material that, when stretched, behaves like a spring with a spring constant of 1.62 x 103 N/m. He accidentally slips and falls freely for 0.959 m before the rope runs out of slack. How m...

**Physics**

A 4.07 x 10-2-kg block is resting on a horizontal frictionless surface and is attached to a horizontal spring whose spring constant is 144 N/m. The block is shoved parallel to the spring axis and is given an initial speed of 10.5 m/s, while the spring is initially unstrained. ...

**Physics**

A 4.07 x 10-2-kg block is resting on a horizontal frictionless surface and is attached to a horizontal spring whose spring constant is 144 N/m. The block is shoved parallel to the spring axis and is given an initial speed of 10.5 m/s, while the spring is initially unstrained. ...

**Physics**

When subjected to a force of compression, the length of a bone (compression Young's modulus 9.4 x 109 N/m2, tensile Young's modulus 1.6 x 1010 N/m2) decreases by 1.5 x 10-5 m. When this same bone is subjected to a tensile force of the same magnitude, by how much does i...

**Math**

To start with, you're not supposed to multiplying anything. M= 176-0.8A. M+ 0.8A=176. We know what m is, so the equation becomes 125 + 0.8A = 176. We rearrange the equation to be 0.8A= 176-125. Now to get A by itself, we divide both sides by 0.8 so then A= (176-125)/0.8

**Math**

So if m= max heart rate, which you know is 125. Then write the equation as. 125=176-0.8A. Now solve for A to get the persons age. You will need to round to get the answer.

**algebria**

So of your population is growing by 1%, then you need to know what 1% of 10,280 is. So 10,280 * 0.01= 102.8. To find the population in 5 years, add 5(102.8) to your starting population. Alternatively, you can just add 102.8 five times to 10,280.

**science**

What is your question?

**physics**

When subjected to a force of compression, the length of a bone (compression Young's modulus 9.4 x 109 N/m2, tensile Young's modulus 1.6 x 1010 N/m2) decreases by 1.5 x 10-5 m. When this same bone is subjected to a tensile force of the same magnitude, by how much does i...

**physics**

A spring (k = 905 N/m) is hanging from the ceiling of an elevator, and a 4.8-kg object is attached to the lower end. By how much does the spring stretch (relative to its unstrained length) when the elevator is accelerating upward at a = 0.74 m/s2?

**physics**

A ball of mass m=0.25 kg is dropped from rest. What is the speed of the ball after it falls two meters?

**Math**

all 6 numbers add up to 55953.77 $2,023.60. $22,046.01 $8,161.59 $10,284.69 $11,023.01 $2,414.88 $55,953.77total The percent listened for 6 numbers above are in order as above are the percents that were calculated (which I don't understand how!) 4.0% 39.0% 15.0 % 18.0% 20....

**Math **

Can you help me ? I need to figure formula if I have $2023.60 what percent is it of $55,953.77? Also need to figure formula if I have $22,046.02.01 what percent is it of $55,953.77?

**Physics**

A space probe is traveling in outer space with a momentum that has a magnitude of 7.84 x 107 kg·m/s. A retrorocket is fired to slow down the probe. It applies a force to the probe that has a magnitude of 1.29 x 106 N and a direction opposite to the probe's motion. ...

**Physics**

A pitcher throws a 0.192-kg baseball, and it approaches the bat at a speed of 43.2 m/s. The bat does 69.8 J of work on the ball in hitting it. Ignoring air resistance, determine the speed of the ball after the ball leaves the bat and is 32.6 m above the point of impact.

**Physics**

An asteroid is moving along a straight line. A force acts along the displacement of the asteroid and slows it down. The asteroid has a mass of 4.5× 104 kg, and the force causes its speed to change from 7000 to 5000m/s. (a) What is the work done by the force? (b) If the a...

**Physics**

two groups of paddlers meet in the middle of a lake. after a brief visit a person in canoe 1 pushes on canoe 2 with a force of 46 N . Mass of canoe 1 is 150 kg and mass of canoe 2 is 250 kg. find acceleration of each canoe

**math**

The pizza is 12/12, meaning it has 12 total slices. If 5 people each had 2 slices (this is what 2/12 means) then: 5* (2/12)= 0.83= 10/12 10/12 is how much pizza was eaten. To figure out how much is left, subtract how much was eaten from the total. (12/12)- (10/12)= 2/12

**Lit**

Use a semicolon. Semicolons are used to separate two independent clauses. So it would something like: "In the nineteenth century, the middle class participated in revolutions to establish liberalism; one way was through literature, and through the revolutions of 1848. The...

**Physics**

A skater with an initial speed of 5.90 m/s stops propelling himself and begins to coast across the ice, eventually coming to rest. Air resistance is negligible. (a) The coefficient of kinetic friction between the ice and the skate blades is 0.125. Find the deceleration caused ...

**Biology**

Basic structural unit of a DNA molecule is called a nucleotide. Basics structural unit an of RNA molecule is also a nucleotide. Basic structural unit of a polypeptide is called an amino acid. DNA is translated into RNA which is transcribed into amino acids, which then link tog...

**Physics**

A 39.7-kg crate rests on a horizontal floor, and a 65.3-kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person.

**Dividing decimals**

How do you solve 49.05 divided by 2.5. Need to see step by step process.

**Physics**

A planet has a mass of 6.15 × 1023 kg and a radius of 3.25 × 106 m. (a) What is the acceleration due to gravity on this planet? (b) How much would a 79.4-kg person weigh on this planet?

**Physics**

A skateboarder shoots off a ramp with a velocity of 5.7 m/s, directed at an angle of 58° above the horizontal. The end of the ramp is 1.3 m above the ground. Let the x axis be parallel to the ground, the +y direction be vertically upward, and take as the origin the point o...

**Physics**

A volleyball is spiked so that it has an initial velocity of 15.6 m/s directed downward at an angle of 56.9 ° below the horizontal. What is the horizontal component of the ball's velocity when the opposing player fields the ball?

**Physics**

An airplane has a mass of 3.25 × 104 kg and takes off under the influence of a constant net force of 2.38 × 104 N. What is the net force that acts on the plane's 74.6-kg pilot?

**physics**

A speeder traveling at 30 m/s passes a motorcycle policeman at rest at the side of the road. The policeman accelerates at 2.4 m/s2. To the nearest tenth of a second how long does it take the policeman to catch the speeder?

**math**

solve for x x-3(x-1)=6x-3-8x a) infinite solutions b)no solution c)0 d)-1 (x-3)(x-1)=-2x-3 so I believe from the information given the answer would be b) no solution. Is this correct?

**math**

a light year is the distance light travels in one year. one light year is about 5.9x10^12 mi. If it takes light 3 months to travel from one star to another, about how far apart are the stars? 5.9x10^12/12*3 I got 1.5x10^12 mi Is this correct?

**math**

during a clinical study, a medical company found 3 out of 70 people experienced a side effect when using a certain medicine. The company predicts 63,000 people will use the medicine next year. How many people are expected to experience a side effect? 3/70=x/63000 18900=70x x=2...

**math**

Which best describes a polynomial? A) a decimal that is non-terminating or non-repeating B) a close-planed figure formed by three or more line segments C)a number greater than one that has exactly two different factors D) an algebraic expression containing one or more terms I ...

**math**

simplify (x^2-3x+6)-(36x^2-18x+6/6) (x^2-3x+6)-(6(6x^2-3x+1/6) cancel the two 6's in the second part of equation x^2-3x-6x^2+3x-1 -5x^2-1 Is This correct? Thanks

**Math**

ok thanks for your help and the tidpit of useful information

**Math**

Hannah plans on going hiking most of the day. It is recommended that she takes at least 3 liters of water with her. She packed 3 water bottles. The bottles she brought are cylinders with a radius of 3cm and a height of 30cm. What is the volume of one bottle to the nearest cubi...

**math**

one candy bar contains 220 calories. If this represents 10% of the total calories a person consumes in one day, find the total number of calories consumed in a day. 220/x=10/100 cross multiply so x=2200 is this correct? thanks

**math**

Sarah collects money for charity while treat-or-treating. This year she collected $15.80. Last year she collected $14.25. Find the percent increase for Sarah's collection from last year to this year to the nearest percent. $15.80-$14.25=$1.55 difference 1.55/14.25 x 100=11...

**math**

solve 3/2x-3=5/2x-5 3(2x-5)=5(2x-3) 6x-15=10x-15 minus 6x to both sides -15=4x-15 add 15 to both sides 0=4x 0/4=4x/4 x=0 Is this correct?

**math**

when 7x^4-49x^3+7x^2 is divided by 7x^2, the quotient is when I divided I got x^2-7x+1 Is this correct?

**math**

Jake buys a bicycle for $200 down and$20 a month for 2 years.What is the expression that represents the total amount he will pay for the bicycle? I did $200+$20(2x12) Is this correct?

**math**

thank you

**math**

The average temperature in the artic circle is -25degrees Celsius. To the nearest integer, what is the average temperature in the artic circle in degrees Fahrenheit? I got -13 degrees I did F=9/5(-25)+32 -45+32=-13 Is this correct?

**math**

simplify 4^8/4^-4 Would this be 4^4 the correct answer?

**math**

the expression 10x^2+6x^3 is the result of applying the distributive property to the expression 2x^2(5+3x). write the expression such that you applied the distributive to your expression it will give the result presented 1) m^2(a+b)+m^3(a+b) for this I got (a+b)(m^2+m^3) 2) 15...

**math**

divide 12a^4+a^3-2a by 2a. I got the quotient of 6a^3+.5a^2-1 Is this correct

**Trig**

Verify the identity. 1/(tanx-secx) + 1/(tanx+secx) = -2tanx

**Math**

A club consists of 8 seniors, 7 juniors, and 4 sophomores. A subcommittee consisting of 3 seniors, 2 juniors, and 1 sophomore will be chosen. How many different such subcommittees are there?

**math**

Part 1 : Store equipment is purchased on January 1, 2002 at a cost of $14,000 and $1,000 was spent on its installation. The depreciation is written-off at 10% on the original cost every year. The books are closed on December 31, every year. Instructions: Prepare a Depreciation...

**Pharmacy Calculaions**

I can't get this right! Please help... Based on the formula below, what quantities of each are needed to make 180 ml of this lotion? Benzyl Benzoate 250 ml Triethanolamine 5 ml Oleic Acid 20 ml Purified water to make 1000 ml

**Physics**

Two objects are connected by a string with a mass less, friction less pulley. The coefficient of friction is .298. The block on the table is 4 kg. What must the mass of the hanging block be so that the block on the table will move with a constant speed?

**Physics**

A 1.1 kg lizard lies on a flat rock tilted. A person decides to tilt the rock hoping that the lizard falls off. The rock is tilted at an angle of 15 degrees with respect to the horizontal. The coefficient between the rock and the lizard is .16. What is the acceleration of the ...

**World History**

What factor led the English to attempt to kill off entire Native American peoples? A. Native Americans provided a good labor source for the Spanish. B. Native Americans had vast wealth to exploit for tribute. C. The Native Americans' large populations were a direct threat....

**Geometry**

EAD

**organic chem**

if sulfuric acid was not added to isopentyl alcohol how would that affect the results

**Chemistry**

A coffee-cup calorimeter initially contains 125 g water at 24.2 degrees celsius. Potassium bromide (10.5 g), also at 24.2 degree celsius, is added to the water, and after the KBr dissolves, the final temperature is 21.1 degrees celsius. Calculate the enthalpy change for diesel...

**Biology**

In ion exchange chromatography, why do you have to be careful not to disturb the resin bed or let air enter the resin bed? I get that it disturbs resolution.. but I'm not sure exactly what to say.

**Chemistry**

A portable electric water heater transfers 255 watts (W) of power to 5.5 L of water, where 1 W = 1 J/s. How much time (in minutes) will it take for the water heater to heat the 5.5 L of water from 25 degrees celsius to 42 degrees celsius? (Assume that the water has a density o...

**Chemistry**

25.0 mL of ethanol (density = 0.789 g/mL) initially at 7.0 degrees celsius is mixed with 35.0 mL of water (density = 1.0 g/mL) initially at 25.3 degrees celsius in an insulated beaker. Assuming that no heat is lost, what is the final temperature of the mixture?

**Algebra**

1. First you need to find the slope of the original line you are given which is 3x + y = 6. The slope is -A/B so it is -3/1 or just -3, m = -3. 2. The slope of a line perpendicular is the negative reciprocal so the slope of the line perpendicular to the given line is 1/3. 3. U...

**chemistry**

Determine the theoretical and percent yield of hydrogen gas is 36 g of water undergoes electrolysis to produce hydrogen and oxygen and 3.8 g of hydrogen is collected.

**Chemistry **

How would you make 100mL of tartrate buffer, pH 3.5, from 0.100 M tartaric acid, 1M NaOH and deionized and distilled H2O? You need to consider the ionization of two the two acidic groups separately.

**Chemisty**

16.72g of sodium acetate trihydride (MW=136 g/mol) is dissolved in 100mL water. To this, 4.00g glacial acetic acid (Ka=2.2x10-5, MW=60.0 g/mol) is added, and distilled water is added to to the 500mL mark. Find the final pH and the molar concentration of the buffer.

**Chemistry **

How would you make 100mL of tartrate buffer, pH 3.5, from 0.100 M tartaric acid, 1M NaOH and deionized and distilled H2O? You need to consider the ionization of two the two acidic groups separately.

**Geometry**

PQR is congruent to DJE. complete the statement below PR is congruent to __, DJ is congruent to __ angle E is congruent to __ 1) PR is congruent to PQ, DJ is congruent to PQ, angle E is congruent to angle R 2) PR is congruent to DE, DJ is congruent to DR, angle E is congruent ...

**trig**

You are sky diving and are trying to land on a target with a radius of 15 m. You land 10 m west and 10 m north of the center of the target. a. Write an inequality to describe the region inside the target area. b. Do you land within the target area? c. If another skydiver lands...

**Physics help!!**

A team of dogs drags a 150 kg sled 1.39 km over a horizontal surface at a constant speed. The coeﬃcient of friction between the sled and the snow is 0.236. The acceleration of gravity is 9.8 m/s^2. Find the work done by the dogs. Also, What is the energy lost due to fri...

**Physics**

Another quick question, what is the ratio K2/K1 of their kinetic energies. Is, it just dividing the second bullet's KE to the first?

**Physics**

I see! Thank you!

**Physics**

Two bullets have masses of 2.4 g and 5.2 g, respectively. Each is ﬁred with a speed of 37.0 m/s. a) What is the kinetic energy of the ﬁrst bullet? b) What is the kinetic energy of the second bullet? I initially used KE=1/2MV^2 and got 1642.8 J, but got it wrong. ...

**Physics help!!**

i got the magnitude i still don't get tan A = Fy/Fx can you explain thoroughly?

**Physics help!!**

A crate is pulled to the right with a force of 80 N, to the left with a force of 125.8 N, upward with a force of 615.4 N, and downward with a force of 248 N. Net external force in the x direction: -45.8 Net external force in the y direction: 367.4 N how do i find the magnitude...

**Physics.. please help!!!!!**

A crate is pulled to the right with a force of 80 N, to the left with a force of 125.8 N, upward with a force of 615.4 N, and downward with a force of 248 N. What is the net external force in the x direction? y direction?? Also.... What is the magnitude of the net external for...

**Physics.. please help!!!!!**

A ball of mass 0.4 kg, initially at rest, is kicked directly toward a fence from a point 20 m away, as shown below. The velocity of the ball as it leaves the kicker’s foot is 16 m/s at angle of 46◦ above the horizontal. The top of the fence is 4 m high. The ball hit...

**Physics.. please help!!!!!**

A person walks 28.2◦ north of east for 3.33 km. Another person walks due north, then due east to arrive at the same location. How far due north would this person walk? How far would this person walk due east?

**Trig!**

The identities cos(a-b)=cos(a)cos(b)sin(a)sin(b) and sin(a-b)=sin(a)cos(b)-cos(a)sin(b) are occasionally useful. Justify them. One method is to use rotation matricies. Another method is to use the established identities for cos(a+b) and sin (a+b).

**chemistry**

If the amount of mercury in a polluted lake is 0.40 ug/mL, what is the total mass of mercury in the lake? (The lake has a surface area of 100 mi squared and an average depth of 25 ft).

**algebra 1 **

I was given this interesting problem: The length of a rectangle is 6 feet longer than its width. The perimeter is less than 48 feet. Write a mathematical expression for the width of the rectangle. How do I go about doing this?

**physics**

A car can go from 0 to 85 km/h in 10 s. If the engine delivered twice the power, how many seconds would it take?

**chemistry**

How many grams are required to make 1.5 L of 3.0 M hydrochloric acid (HCl) solution?

**chemistry**

How many grams are required to make 1.5 L of 3.0 M hydrochloric acid (HCl) solution?

**physics**

how many revolutions per minute would a 15 m ferris wheel need to make for passengers to feel weightless at the top?

**3rd grade**

Could you divide 14 shirts into equal groups

**Chemistry**

Hydrogen and oxygen gas combine explosively to produce water. Write a balanced chemical equation for this process. If 10 mol of hydrogen reacted with oxygen, what volume of liquid water could be produced?

**PRE-CALC**

I got a different answer than all of you guys :P HINT: To actually visualize the problem, draw it out! :) Obviously the dimensions of the painting are: w and 3+w We know that the frame is 12 in wide, aka 1 ft wide. And we also are given that the total area of the painting and ...

**Math values**

The value of cos^-1(-(sqrt3)/2) is what?

**Math**

Lee has two tests to study for: Chemistry and French. She plans to study for up to 13h in total. She will spend at least 4 hours studying Chemistry and up to 6 hours studying French. Let x represent the number of hours she will spend studying Chemistry, and y the number of hou...

**Healthcare Management**

What are the most important functions of health information management? (thank you in advance for your help)

**Physics**

A satellite has an orbit with pedigree 175 km and apogee 181,200 km. What is the period of the orbit? >>I'm not sure what the associated equation is. I tried the problem using the average radius in the period equation but it didn't work. Please help!

**Math**

How many different functions are there from a set with 10 elements to sets with the following numbers of elements? a) 2 b) 3 c) 4 d) 5

**Math**

How many different functions are there from a set with 10 elements to sets with the following numbers of elements? a) 2 b) 3 c) 4 d) 5

**physics**

A car engine accelerates at a constant rate from 170 rpm to 3050 rpm in 7 seconds. I have found that at t=0, the angular velocity (omega)=17.8 rad/s, the angular acceleration (alpha)= 43.1 rad/s^2, the tangential acceleration = 7.76 m/s^2, and the centripetal acceleration is 5...

**Pre-calculus**

Given the following values for f(t): t : f(t) 3 : -7 6 : 6 9 : 19 12 : 6 15 : -7 18 : 6 a) What is the period, frequency, midline, amplitude, maximum, and minimum? b)Find a possible formula for f(t) c)Find the domain and range of f(t) d)Find a formula for an inverse function o...

**college earth science and astronomy**

Thank you very much bobpursley! This has been quite the challenge to learn without the benefit of a teacher. I want to run my answers past and see if I have calculated correctly. energy= 250 * 2.5 = 625 Calories Then solar energy flux will be 250 *2.5 (625) / 63.6 * 10 (636) c...

**college earth science and astronomy**

This isn't homework as much as I am trying to learn this on my own. I am trying to perform an experiment on solar power. I measured and recorded the volume (V= 250 mL) and mass (M= 250 g) of water in a cup. I then recorded the initial temperature(32 degrees celcius) of the...

**Chemistry**

I had to find the numbers of atoms in 2 Al (NOsubscript 3)subscript 3. I got 16, but the answer in my book is 26. Who is incorret? Thanks!!!

**social studies**

Are you asking about symbols used in ancient writing? If you are, an example is hieroglyphics (don't trust me that I spelled that right). Hope I helped you!

**Another algebra**

Determine the number of positive integers n that satisfy: 1/2 < n/n+1 < 99/101 I don't know how to solve this besides plugging in random numbers, which would take all day. Any other suggestions for a faster way to solve it? Thank you!

**Algebra**

What is the length of the interval of solutions to the inequality 1 ( is less than or equal to) 3-4x (is less than or equal to) 9? I presume that I just plug in numbers for x? The problem is, that all the positive numbers I've tried have made them way less than one, when i...

**math**

Try to make two equations, one for each phone company. First plan: y = .10x + 18 Second plan: y = .15x Try plugging in numbers until the two equations have the same y. If you need anymore explanations, just respond back. Hope I helped!

**Math**

woooow really mature. "yo moma" oh that's so funny...what are we, in third grade? it's "aflyerquacker"