Sunday

November 29, 2015
Total # Posts: 771

**Calculus**

The amount remaining of a radioactive substance after t hours is given by A(t) = 100ekt. After 12 hours, the initial amount has decreased by 4%. How much remains after 48 hours? What is the half-life of the substance?
*November 23, 2015*

**Physics**

Damon, Where do you suggest I look for an approximate mph figure. I realize we are ignoring key factors, but surely someone can give me an educated guess - - e.g. the body would hit the ground at 100 mph plus or minus 10 mph. Thanks
*November 20, 2015*

**Physics**

A 180 pound body is dropped from a helicopter 5 miles (26400 ft.) up - - what maximum speed would the body attain, in miles per hour, before hitting the ground? Disregard gravity, air density, etc. factors, a very rough approximation is all that is needed. Thanks.
*November 20, 2015*

**Physics**

If a 180 pound body is dropped from an airplane 5 miles (26400 ft.) up: a/ how long would it take for the body to reach the ground? b/ what would be the maximum speed the body would attain in miles per hour? Close approximations are all that are required here. Thanks.
*November 20, 2015*

**Physics**

If a 180 pound body was dropped from a plane 5 miles in the air - how long would it take for the body to reach the ground?
*November 19, 2015*

**math**

Independent random samples, each containing 800 observations, were selected from two binomial populations. The samples from populations 1 and 2 produced 320 and 400 successes, respectively. Construct a 90% confidence interval for the true difference in population proportions ...
*November 18, 2015*

**math**

Suppose x has a binomial probability distribution with n = 200 and p = 0.60. Use the normal approximation to the binomial to find P (X > 130).
*November 18, 2015*

**Physics**

The instruments attached to a balloon have a mass of 5kg. The balloon is released and exerts an upward force of 100 N. After the balloon has accelerated for 10s, the instruments are released. What is the velocity of the instruments at the moment of release?
*November 2, 2015*

**Physics**

The driver of a car is going 90 km/hr suddenly sees a barrier40m ahead. It takes the driver .75 sec to apply the brakes, and the average acceleration during braking is -10m/s^2. Will the car hit the barrier and use calculation to show work.
*October 31, 2015*

**Physics**

10.234234
*October 29, 2015*

**Trig**

mercury rotates around the sun in approx. 89 earth days (or 7,689,600 s. use a calculator to approximate its angular speed. choices: 4.09x10^-7 0.035 0.071 8.17x10^-7
*October 21, 2015*

**Did you read The Pig Man And Me**

John Quinn does not explain the rule about the paddle to Paul, the narrator of “The Pigman & Me.” How does this one action affect the rest of the essay?
*October 11, 2015*

**HELP SCIENCE ASAP**

How are fish, amphibians, reptiles, and birds alike? How are they different? Include at least two similarities and two differences.
*October 7, 2015*

**ela**

Which section of a personal narrative requires the most development? a. introduction b. conclusion c. character introduction d. plot my answer is a can you check it for me
*October 5, 2015*

**ELA HELP FAST**

Which section of a personal narrative requires the most development? a. introduction b. conclusion c. character introduction d. plot
*October 5, 2015*

**Social Studies**

what do you mean
*October 5, 2015*

**Social Studies**

What examples are given of a limited government and an unlimited government in the section? How did each type of government affect its citizens? Japans government
*October 5, 2015*

**History**

Its fine i got my dad to help me. Thank you
*September 13, 2015*

**History**

"The renewable energies roadmap unveiled earlier this month by the Commission sets a target of 20% for the share of total energy supply to come from renewable sources. “It is not the first time that targets for renewable energy have been fixed. In 1997, the European ...
*September 13, 2015*

**psychology**

Dr. Jefferson is conducting an experiment in which she is interested in the effects of caffeine on visuospatial ability in adult participants. She conducts an experiment in which she gives one group a pill containing 20mg of caffeine and a second group a placebo pill. One hour...
*September 13, 2015*

**Psychology**

A researcher has conducted an experiment in which she has given participants a placebo, 10mg, and 20mg of a drug. She then measured their anxiety, blood pressure, and heart rate in response to the drug. How many levels does this experiment’s independent variable have?
*September 13, 2015*

**Psy 326**

We use _______________ to communicate the patterns and distribution of our measured variables.
*August 24, 2015*

**physics**

A bird watcher meanders through the woods, walking 0.744 km due east, 0.925 km due south, and 3.97 km in a direction 18.3 ° north of west. The time required for this trip is 1.765 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average ...
*August 14, 2015*

**Physics**

Knowing that you have the mass of each sun, M1=M2=M which is 2x10^30 kg, and you have the distance between the two stars a=1 AU, you can use Kepler's third law to solve for the period in seconds: p^2=((4pi)^2(a)^3)/(Gm) where p is measured in seconds, a is measured in ...
*August 14, 2015*

**physics**

A bird watcher meanders through the woods, walking 0.544 km due east, 0.925 km due south, and 3.58 km in a direction 17.3 ° north of west. The time required for this trip is 1.957 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.
*August 12, 2015*

**Langauge Please Help**

The novel to kill a mockingbird feature a main character named scout. Scout is also the voice that tells the story. What point of view is used in the novel? A.First Person B.Third-Person Limited<----------- C.Third-Person Omniscient The prefix a- can mean "none" ...
*August 11, 2015*

**Math**

A ball is thrown, and its height is recorded a number of different times. The ball reaches a maximum height of 20 m after 1.5 s. How do you sketch this relation from just a vertex. Grade 11 functions
*July 18, 2015*

**Math- algebra **

An experiment stain of bacteria is being used to treat an oil spill. A colony of 2^13 cells will be sufficient to ocean up the spill. If the colony is started with a single cell, and cells increase in number by splitting every 15 minutes, in how many hours will the colony ...
*June 5, 2015*

**Algebra 2**

An object is moving at a speed of 3 + 2 𝑓𝑡/𝑠. How long would it take the object to travel 20 𝑓𝑡? [looking for actual solution and not decimal approximation]
*May 1, 2015*

**Chemistry physics**

3.25x10-3 kg of gold is deposited onto the negative electrode of an electrolytic cell in a period of 2.78 hours, what is the current through this cell in amperes? Assume that the gold ions carry one elementary unit of charge
*March 31, 2015*

**Physics**

If 3.25x10-3 kg of gold is deposited onto the negative electrode of an electrolytic cell in a period of 2.78 hours, what is the current through this cell in amperes? Assume that the gold ions carry one elementary unit of charge
*March 31, 2015*

**Math**

Would it be 122?
*March 15, 2015*

**Math**

If the standard error of measurement is 3, and a person scores 125, Standard error of measurement with one standard deviation would put the score at ____?
*March 15, 2015*

**math**

A rectangular piece of carpet is place on the floor of a rectangular room leaving a margin of 1 m around it. If the room measures 8 m by 6 m find the area of the room not covered by the carpet.
*March 10, 2015*

**Physics**

Carl hits a 0.05 kg golf ball giving it a speed of 65 m/s. What impulse does he impact to the ball?
*March 6, 2015*

**Calculus (Partial Derivatives)**

A car dealer determines that if gasoline-electric hybrid automobiles are sold for x dollars apiece and the price of gasoline is y cents per gallon, then approximately H hybrid cars will be sold each year, where H(x,y)=6000−13x^(1/2)+2(0.1y+20)^(3/2). She estimates that t...
*March 4, 2015*

**Calculus (Partial Derivatives)**

A car dealer determines that if gasoline-electric hybrid automobiles are sold for x dollars apiece and the price of gasoline is y cents per gallon, then approximately H hybrid cars will be sold each year, where H(x,y)=6000−13x^(1/2)+2(0.1y+20)^(3/2). She estimates that ...
*February 28, 2015*

**Calculus (Partial Derivatives)**

It's supposed to be Q(x,y)=40xy^(1/5)
*February 28, 2015*

**Calculus (Partial Derivatives)**

Using x hours of skilled labor and y hours of unskilled labor, a manufacturer can produce Q(x,y)=40xy1/5 units each week. Currently 20 hours of skilled labor and 243 hours of unskilled labor are being used. Suppose the manufacturer reduces the skilled labor level by 2 hours ...
*February 28, 2015*

**Economics**

1. How does the current anti-corruption movement in China affect relatively tax free countries(ex. monocao, switerland etc.)? 2. EU relation with China
*February 26, 2015*

**physics**

Two horizontal forces, and , are acting on a box, but only is shown in the drawing. can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the surface. Suppose that = +8.3 N and the mass of the box is 4.5 kg...
*February 19, 2015*

**Calculus**

Since it's compunded continuously, you use Present Value = Integrate from 0-T f(t)e^(-rt). It doesn't give a time limit, so we'll assume it's infinte. Integrate from 0-Infinity 110e^(-.08t) =[-1375e^-.08(Inifinity)]-[-135e^-.08(0)] = 0-(-1375) = 1375
*February 13, 2015*

**Chemistry**

calculate the density of NH3 at S650mm of Hg
*February 11, 2015*

**Bobpursley**

Look at my problem again please thanks
*February 5, 2015*

**Physics**

The spring force should be 588 N/m and velocity 0.700 m/s
*February 5, 2015*

**Physics**

3 kg object is fastened to a light spring with the intervening cord passing over a pulley. The pulley is frictionless and it's inertia may been neglected. The object is released from rest when the spring is unstretched. If the object drops 10 cm before stopping find the ...
*February 5, 2015*

**physics**

Why no one answer me
*January 20, 2015*

**physics**

You set your stationary bike on a high 80 N friction like resistive force and cycle for 30 min at speed of 8 m/s. Your body is 10% efficient at converting chemical energy in your body into mechanical work. What is your internal chemical energy change? How long must you bike to...
*January 20, 2015*

**physics**

A fire engine must lift 30 kg of water a vertical distance of 20 m each second. What is the amount of power needed for the water pump for this fire hose? P=W/t=Fd/t=mgd/t (30)(9.8)(20)/1= 5880 W is that right?
*January 20, 2015*

**physics**

A 75 kg bobsled is pushed along a horizontal surface by two athletes. After the bobsled is pushed a distance of 4.5 m starting from an initial speed of 1.2 m/s, its speed is 6.0 m/s. What is the change in kinetic energy? Find the magnitude of the net force on the bobsled.
*December 15, 2014*

**physics**

A student wearing frictionless in-line skates on a horizontal surface is pushed, from rest, by a friend with a constant force of 45 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 352 J?
*December 15, 2014*

**physics**

How much work is required to accelerate a 0.145 kg baseball from rest, to a speed of 38.7 m/s?
*December 15, 2014*

**Calculus**

Is 72 the correct answer?
*December 7, 2014*

**Calculus**

Find the area of the region bounded by the curves y=12-x^2 and y=x^2-6. Hint:The answer should be a whole number.
*December 7, 2014*

**Chemistry (Titrations)**

In order to standardize a KMnO4 solution, 0.2848 g Fe(NH4)2(SO4)2·6H2O was dissolved in 25 mL 0.18 M H2SO4. The KMnO4 solution was added to the Fe(NH4)2(SO4)2·6H2O solution until a pale pink color persisted. The titration took 24.2 mL of KMnO4 solution. What is ...
*November 30, 2014*

**business statistics**

10.55 Consider an experiment with four groups, with eight values in each. For the ANOVA summary table below, fill in all the missing results: Source Degrees of Freedom Sum of Squares Mean Square (Variance) F Among groups c - 1 = ? SSA = ? MSA = 80 FSTAT = ? Within groups n - c...
*November 27, 2014*

**Math**

how to write 4(x+2)+3x+2(x-y) in the distribt. property form
*November 23, 2014*

**Chemistry**

Calculate the pH of a 1.19M sodium formate, HCOONa, solution.
*November 23, 2014*

**Chemistry**

Calculate the pH of a buffer solution made by mixing 231 mL of a 1.04M trimethylamine (CH3)3N solution with 176 mL of a 1.38M trimethylammonia chloride, (CH3)3NHCl solution. Enter your answer to TWO decimal places. DO NOT use scientific notation.
*November 23, 2014*

**Chemistry**

How many grams of nitric acid (HNO3) must be dissolved in 590 ml of water to make a solution with a pOH = 10.1? Select one: a. 2.9 x 10-9 g b. 7.9 x 10-3 g c. 4.7 x 10-3 g d. 7.9 x 10-6 g e. 7.4 x 10-5 g
*November 23, 2014*

**physics**

A bee flies to a flower 583 m due south of its hive. The bee’s speed in still air is 0.68 m/s, and there is a wind blowing toward the south at 0.16 m/s. How long will it take the bee to travel to the flower and back to the hive? Answer in units of s
*November 18, 2014*

**Chemistry (Acid&Base)**

How many mL of 0.203 M HCl(aq) are required to prepare a diluted solution that has a concentration of 0.0433 M in a 100-mL volumetric flask?
*November 16, 2014*

**Chemistry**

Consider the reaction 2 SO2(g) + O2(g) in equilibrium with 2 SO3(g) . At 25°C delta H° = -197.78 kJ and delta S° = -187.95 J/K. Using this information, calculate the equilibrium constant for the reaction at -32°C. (R = 8.314 J/K) Enter your answer using TWO ...
*November 16, 2014*

**statistics**

It seems that people are choosing or finding it necessary to work later in life. Random samples of 200 men and 200 women age 65 or older were selected, and 80 men and 59 women were found to be working. At á = 0.01, can it be concluded that the proportions are different
*November 15, 2014*

**Statistics**

Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that more than three of them will experience a bad side effect?
*November 14, 2014*

**physics**

Rubber tires and wet blacktop have a coefficient of kinetic friction of 0.5. A pickup truck with a mass 750 kg traveling 30.0 m/s skids to a stop. (a) what is the size and direction of the frictional force that the road exerts on the truck? (b) Find the acceleration of the ...
*November 11, 2014*

**calculus related rates **

Boyle’s law for the expansion of a gas is PV = k, where P is the pressure (in pounds per unit of area), V is the volume of the gas, and k is a constant. Find the expression that shows the rate of change of the pressure as related to the rate of change of the volume. dP/...
*November 11, 2014*

**Physics**

A dog sled weighing 750 lb is pulled over level snow at a uniform speed by a dog team exerting a force of 60 lb. find the coefficient of friction.
*November 11, 2014*

**physics**

A plane cruising at 247 m/s accelerates at 28 m/s 2 for 8.7 s.How far will it have traveled in that time?
*October 22, 2014*

**physics**

A car travels in a straight line for 2.8 h at a constant speed of 53 km/h . What is its acceleration? Answer in units of m/s 2
*October 21, 2014*

**physics**

Water is poured into a container that has a leak.The mass 'm' of the water is given as a function of time 't' by, m=5t^0.8 -3t + 20 , with t>=0, mass in grams and t in seconds A) at what time is the water mass greatest,and B) what is the greatest mass? In ...
*October 19, 2014*

**Physics **

The space shuttle, with an initial mass M = 2.41×106 kg, is launched from the surface of the earth with an initial net acceleration a = 26.1 m/s^2. The rate of fuel consumption is R = 6.90×103 kg/s. The shuttle reaches outer space with a velocity of vo = 4632. m/s...
*October 13, 2014*

**physics **

A space probe is to be put into a circular orbit of radius 42.00 km about an asteroid. At this radius the magnitude of the gravitational acceleration, normally referred to as the "gravitational field", is 1.00×10-3 meters per second squared. What speed, in ...
*October 13, 2014*

**help**

If BaSO4 ppt is isn't washed or dried adequately how will this effect the sulfate percent error determination?
*October 12, 2014*

**Chem lab**

Student Calamity reported a final yield of 50%. List four things she might have done wrong to account for this yield. Student Overachiever reported a final yield of 115%. List two things he might have done wrong to account for this yield.
*October 11, 2014*

**chemistry**

you have not added enough sodium hydroxide to precipitate all the copper as copper hydroxide. How could you tell that not all the copper had precipitated?
*October 11, 2014*

**physics**

A mass m = 6.0 kg is attached to the lower end of a massless string of length L = 27.0 cm. The upper end of the string is held fixed. Suppose that the mass moves in a circle at constant speed, and that the string makes an angle theta = 28° with the vertical, as shown in ...
*October 7, 2014*

**statistics**

There are two companies that sell the medication, Company A and Company B. Company A’s tablets have a mean of 5 mg of medication and Company B’s tablets also have a mean amount of 5 mg of medication. This information would lead you to believe that it would make no ...
*September 28, 2014*

**Math**

Find the locus of points that satisfy (a) |z+1| = |z+i| (b) Re z = |z-1| and sketch them in the complex plane.
*September 22, 2014*

**AP Alegebra**

simplify (sqrt(x)+1)/(sqrt(x)-1)
*September 7, 2014*

**Physics**

just submitted the answer... to two sig figs it would be 53000 or 5.3x10^4
*August 27, 2014*

**math**

have 10 boxes each box contains 50 peices and we're selling for 8.00 per box. If I had to repackag them into 20 pieces each how much would I sell the repacked boxes for ? And how much for the quantity ?
*August 8, 2014*

**Physics**

Two charged particles are fixed on the x-axis 11 cm apart. The one on the left has a net charge of +25uc and the one on the right has a net charge of -15uc. What is the magnitude of the electric field 15 cm to the right of the negative charge? How do you solve this problem? ...
*August 3, 2014*

**Math**

For a party; Mike is making an eight layer torte, which consists of eight 7-inch diameter cake layers with a cream topping on each. He knows that one recipe of cream topping will cover 55 square inches of cake. How many batches of the topping must he make to complete his torte...
*June 12, 2014*

**Math**

A model plane flies 18ft per 2 seconds. What is the plane's speed in miles per hour? Round to the nearest tenths.
*April 27, 2014*

**Math**

Write an algebraic expression for "15 less than the product of the square of x and 5."
*April 20, 2014*

**CHEMISTRY**

WHAT IS THE EMPIRICAL FORMULA FOR A COMPOUND THAT HAS 200GRAMS. 97.30 GRAMS OF CARBON, 16.22 GRAMS OF HYDROGEN, AND THE REST IS OXYGEN?
*April 12, 2014*

**Math**

Jim paid $ 5.55 for 1 notepad and 7 pencils. Anne paid $ 12.28 for 3 notepads and 2 pencils. How much does each notepad cost? Show all work
*April 7, 2014*

**statistic**

Roll two 6-sided dice and examine their sum. a) How long will it take to roll "snake-eyes" (a pair of ones)? b) What is the probability of rolling a sum of 7 on the first roll? c) What is the probability of rolling a sum of 7 on the fourth roll? d) What is the ...
*April 1, 2014*

**College Physics**

A doubly charged ion is accelerated to an energy of 33.0 keV by the electric field between two parallel conducting plates separated by 1.70 cm. What is the electric field strength between the plates?
*March 24, 2014*

**math**

If a took a loan of $12000 for one year at 9.5% simple interest what would be my interest
*March 19, 2014*

**math**

if a took a loan out for $12000 for one year at 10% simple discount what would be my interest
*March 19, 2014*

**Chem**

When 100mL of 0.60mol per liter K3BO3 is added to 200 mL of 0.40 mol per liter Ca3(BO3)2 Find a)moles of K3BO b) moles of Ca(BO3)2 c)final concentration of K+ d)final concentration of Ca+2 e) final concentration of BO3 negative 3
*March 19, 2014*

**Chem**

In the lab a 3.3mol per liter solution was prepared by adding H2O to 140mL of a 4.3mol Per Liter solution of HCL. How much water was added?
*March 19, 2014*

**statistics**

a0 7
*February 16, 2014*

**Math**

It's actually C
*February 5, 2014*

**math**

factor 2x^2+7x+6=0
*January 26, 2014*

**transportation economic**

In your own words, describe the meaning of marginal cost. You normally buy a crate of wine for $75. One crate has 6 bottles of wine. After a month, the store clerk informs you that the same crate of wine now costs $82. However, there are 7 bottles in a crate. To the nearest ...
*January 19, 2014*

**biology**

if there is no oxygen for the glycolysis what process would that be called?
*November 6, 2013*