# shelby

Popular questions and responses by shelby-
## Chemistry

The density of dry air measured at 25 degrees Celsius is 1.19x10 to the negative 3rd power. What is the volume of 50.0g of air?

*asked on September 23, 2012* -
## physics

A ball is thrown upward at a speed v0 at an angle of 52.0˚ above the horizontal. It reaches a maximum height of 7.3 m. How high would this ball go if it were thrown straight upward at speed v0?

*asked on February 18, 2012* -
## economics

Suppose that people consume only three goods, as shown in this table: (5 Marks) Tennis Balls Tennis Racquets Gatorade 1998 price $2 $40 $1 1998 quantity 100 10 200 1999 price $2 $60 $2 1999 quantity 100 10 200 What is the percentage change in the price of

*asked on September 25, 2006* -
## phyics

Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the average velocity of the runner. Express your answer in meters per second to the nearest integer.

*asked on September 12, 2015* -
## math

answers to what kind of shoes does a frog wear(the coordinate thingies only)

*asked on January 18, 2011* -
## Algebra

An aircraft factory manufactures airplane engines. The unit cost C (the cost in dollars to make each airplane engine) depends on the number of engines made. If x engines are made, then the unit cost is given by the function =Cx+−0.2x248x21,748 . What is

*asked on March 17, 2017* -
## Physics

1. The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very

*asked on December 11, 2016* -
## Chemistry

For another picnic you want to make hamburgers with pickles, again without having any left over. You need to balance the number of packages of buns (which usually contain 8 buns) with the number of packages of hamburger patties (which usually contain 12

*asked on September 8, 2012* -
## social studies

The addition of which territories increased Spanish power under Charles V? A. the Holy Roman Empire and the Netherlands B. Turkey and Egypt C. Italy and Great Britain D. France and northern Africa Which of the following supported the arts in Spain, leading

*asked on November 9, 2018* -
## geometry

Find angle A if angle A is supplementary to angle B, angle B is supplementary to angle C, angle B equals 12x plus 8, and angle C equals 8x minus 8

*asked on September 10, 2012* -
## Math

in a fifth grade class, 3/4 of the students like to go to the movies. of the students who like to go to the movies, 2/3 of them like action movies. of the students who like to go to action movies, 4/5 of them also like comedies. what fraction of the

*asked on January 27, 2017* -
## Math

Given that force 1=60 pounds and force 2=90 pounds, find the angle between the forces if the magnitude of the resultant force is 50 pounds. Round answer to the nearest degree and show work.

*asked on April 27, 2011* -
## PHYSICS HELP!

A typical propeller of a turbine used to generate electricity from the wind consists of three blades as in the figure below. Each blade has a length of L = 33 m and a mass of m = 415 kg. The propeller rotates at the rate of 21 rev/min. 120degree angle

*asked on October 31, 2012* -
## geometry

In the rhombus, m1 = 18x, m2 = x + y, and m3 = 30z. Find the value of the variables x,y, and z

*asked on January 17, 2012* -
## physics

A flat (unbanked) curve on a highway has a radius of 220m. A car rounds the curve at a speed of 25m/s. What is the minimum coefficient of friction that will prevent sliding?

*asked on March 28, 2015* -
## MUSIC

1. What is the difference between composition and improvisation? Choose the correct. A. Composition is the art of making music spontaneously, while improvisations are carefully planned. B. Improvisation is the art of making music spontaneously, while

*asked on February 22, 2016* -
## math

out of 32 students in a class 5 said they ride their bikes to school based on these results predict how many of the 800 students in the school ride their bikes to school

*asked on November 30, 2011* -
## Physics

In the absence of air resistance, a projectile is launched from and returns to ground level. It follows a trajectory similar to that shown in Figure 3.10 and has a range of 29 m. Suppose the launch speed is doubled, and the projectile is fired at the same

*asked on September 12, 2016* -
## Physics

The figure (Figure 1) shows a model of a crane that may be mounted on a truck.A rigid uniform horizontal bar of mass m1 = 80.0 kg and length L = 5.30 m is supported by two vertical massless strings. String A is attached at a distance d = 1.90 m from the

*asked on March 22, 2016* -
## College algebra

Find an nth degree polynomial. N=4, 2i and 3i are zeros, f (-1)=50

*asked on April 15, 2018* -
## physics

The Wall of Death in an amusement park is comprised of a vertical cylinder that can spin around the vertical axis. Riders stand against the wall of the spinning cylinder and the floor falls away leaving the riders held up by friction. The radius of the

*asked on February 13, 2008* -
## Geometry

c. Given angle ABC has angle bisector BD, where AB = CB, find the value of x if AD = 5x + 10 and DC = 28 - x. Do I just set them equal to each other ?

*asked on July 4, 2019* -
## Trigonometry

Graph the function y=2sin(x-2pi/3). To draw the graph, plot all x-intercepts, minima and maxima within on period. I need to graph at least 5 points. I have -pi, 0, pi, 2pi, 3pi, and 4pi along the x-axis

*asked on March 24, 2014* -
## biology

i need a short story about a ecosystem that is disturbed and undergoes succession

*asked on May 17, 2011* -
## Geometry

a. Find the length of the midsegment of an equilateral triangle with side lengths of 12.5 cm. b. Given that UT is the perpendicular bisector of AB, where T is on AB, find the length of AT given AT = 3x + 6 and TB = 42 - x. c. Given angle ABC has angle

*asked on July 4, 2019* -
## Chemistry

Maleic acid is a carbon-hydrogen-oxygen compound used in dyeing and finishing fabrics and as a preservative of oils and fats. * In a combustion analysis, a 1.054-\rm g sample of maleic acid yields 1.599 \rm g of \rm CO_2 and 0.327 \rm g of \rm H_2O. * When

*asked on April 24, 2012* -
## Statistics

A university has 1,000 computers available for students to use. Each computer has a 250-gigabyte hard drive. The university wants to estimate the space occupied on the hard drives. A random sample of 100 computers showed a mean of 115 gigabytes used with a

*asked on October 27, 2013* -
## physics

A ballistic pendulum, as shown in the figure, was a device used in the past century to measure the speed of bullets. The pendulum consists of a large block of wood suspended from long wires. Initially, the pendulum is at rest. The bullet strikes the block

*asked on March 4, 2008* -
## Calculus

A farmer has 120 meters of wire fencing to make enclosures for his pigs and cows. The rectangular enclosure he is considering will have one side up against a barn (in the center of one side that is 150 meters long, so the enclosure won't require fencing

*asked on October 30, 2012* -
## Physics

1. The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very

*asked on December 11, 2016* -
## chem

1. Since the gas in your graduated cylinder is a mixture of butane and water vapor, you must determine the partial pressure of the butane, Pbutane, alone. To do this, consult a reference and record the partial pressure of the water vapor, Pwater, at the

*asked on March 8, 2018* -
## physics

In a simple model of the wind speed associated with hurricane Emily, we assume there is calm eye 10.0 km in radius. The winds, which extend to a height of 5550 m, begin with a speed of 208.0 km/hr at the eye wall and decrease linearly with radial distance

*asked on March 19, 2008* -
## English

A verb phrase that acts as a noun is called a? participial. adverbial. infinitive. gerund. Which of the following is the prepositional phrase in the sentence below? Applause came from the bleachers. A) Applause came B) came from C) from D) from the

*asked on January 12, 2014* -
## geometry

a rectangle is 80 cm long and 20 cm wide. find, to the nearest degree, the acute angle formed at the intersections of the diagonals.

*asked on March 4, 2009* -
## math

Explain how you can find 3/8% of $800? Not sure how to write it out, I know the answer is 3.

*asked on May 7, 2012* -
## algebra

h = -16t2 + 32t + 84. find the maximum height how many seconds will it take to reach the ground

*asked on May 10, 2019* -
## Chemistry

What is the molarity of an aqueous solution that is 6.44% glucose (C6H12O6) by mass? (Assume a density of 1.03 g/mL for the solution.)

*asked on March 16, 2014* -
## math

when a child flying a kite has let out 50 m of string the string makes an angle of 55 degrees with the ground. how high is the kite

*asked on January 20, 2011* -
## physics

At the top of a hill, a roller coaster has 67,500 J of kinetic energy and 290,000 J of potential energy. Gradually, the roller coaster comes to a stop due to friction. If the roller coaster has 30,000 J of potential energy when it stops, how much heat

*asked on May 21, 2014* -
## geometry

a tree grew at a 3 degree slant from the vertical. at a point 60 feet from the tree, the angle of elevation to the top of the tree is 14 degrees. find the height of the tree to the nearest tenth of a foot.

*asked on December 11, 2012* -
## physics

Three blocks are located on a horizontal table. The coefficient of kinetic friction between the blocks and the table is 0.276. They are connected by a massless cord, as shown in the figure below, and pulled to the right. The masses of the three blocks are

*asked on February 13, 2008* -
## Biochemistry

In naming polypeptides, if asparagine is the second peptide from the N terminal, would it be named asparagyl? Would aspartate be aspartyl if it is the second peptide from the N terminal of a polypeptide?

*asked on July 25, 2012* -
## Physics

A VW Beetle goes from 0 to 46.0 mi/h with an acceleration of +2.35 m/s2. (a) How much time does it take for the Beetle to reach this speed? (b) A top-fuel dragster can go from 0 to 46.0 mi/h in 0.750 s. Find the acceleration (in m/s2) of the dragster.

*asked on September 12, 2016* -
## math

A car traveled 63 miles on 3 gallons of gas. What proportion can you set up to determine how many miles, m, the car can travel on 7 gallons of gas?

*asked on March 7, 2016* -
## Chemistry

How many mL of 0.122 M Na2CO3 would be needed to precipitate all of the copper ions in 23.7 mL of 0.167 M CuSO4? How many grams of CuCO3 could be recovered?

*asked on November 4, 2014* -
## macro economics

Suppose that the residents of Veggieland spend all of their income on cauliflower, broccoli, and carrots. In 1998 they buy 100 heads of cauliflower for $200,50 bunches of broccoli for $75, and 500 carrots for $50. In 1999 they buy 75 heads of cauliflower

*asked on September 26, 2006* -
## geometry!!

Find the lengths of the diagonals of this trapezoid. when the given length for the sides are (-b,c), (b,c),(a,0), (a,0)

*asked on January 18, 2012* -
## geometry!!

Find the lengths of the diagonals of this trapezoid. when the given length for the sides are (-b,c), (b,c),(a,0), (a,0)

*asked on January 18, 2012* -
## physics

Three blocks are located on a horizontal table. The coefficient of kinetic friction between the blocks and the table is 0.276. They are connected by a massless cord, as shown in the figure below, and pulled to the right. The masses of the three blocks are

*asked on February 12, 2008* -
## algebra

a motorboat can maintain a constant speed of 11 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 21 minutes; the return trip takes 1 minutes. That is the speed of the current?

*asked on January 27, 2011* -
## physics

A golfer, standing on a fairway, hits a shot to a green that is elevated 5.39 m above where she is standing. If the ball leaves her club with a velocity of 43.1 m/s at an angle of 45.9 ° above the ground, find the time that the ball is in the air before

*asked on February 18, 2012* -
## economics

Suppose that the residents of Veggieland spend all of their income on cauliflower, broccoli, and carrots. In 1998 they buy 100 heads of cauliflower for $200,50 bunches of broccoli for $75, and 500 carrots for $50. In 1999 they buy 75 heads of cauliflower

*asked on September 25, 2006* -
## penn foster

1. A 30 kg dog is receiving fluids at a rate of 40 mL/hour. It needs a drug added to 500 mL of fluids so that it receives 2 mg/kg each hour. The drug has a strength of 2%. What volume of drug will you add? A.15ml B.37.5ml C.12.5ml D.3ml

*asked on May 25, 2016* -
## physics

What wavelength of sound would a bat need to detect a 1cm diameter mosquito? Also, if it took 0.3 seconds for sound to return to a moth how far away would the moth be?

*asked on April 11, 2013* -
## physics

A car is traveling 15 m/s when the driver sees a child standing on the road. He takes 0.8 s to react, then steps on the brakes and slows at 8.0 m/s2. How far does the car go before it stops?

*asked on September 16, 2012* -
## physics

After leaving the end of a ski ramp, a ski jumper lands downhill at a point that is displaced 44.5 m horizontally from the end of the ramp. His velocity, just before landing, is 15.4 m/s and points in a direction 35.1 ° below the horizontal. Neglecting

*asked on February 18, 2012* -
## physics

A 2490 kg demolition ball swings at the end of a 35.9 m cable on the arc of a vertical circle. At the lowest point of the swing, the ball is moving at a speed of 7.26 m/s. Determine the tension in the cable.

*asked on February 19, 2012* -
## math

The area of a parallelogram is 420 centimeters squared and the height is 35 cm. Find the corresponding base. Be sure to show all work and label your answer

*asked on May 4, 2013* -
## physic

1) if you live 10.0 km from your school and the bus takes 0.53 h to reach the school driving due east, what is the average velocity of the bus? 2) To qualify for the finals in a racing event, a race car must achieve an average speed of 250 km/h on a track

*asked on October 14, 2009* -
## physics

In a city grid, each block on the east-west streets is 180 meters long. Each block on the north-south streets is also 180 meters long. A walker walks 4 blocks north and then 3 blocks east. How much farther did the walker travel than the actual distance

*asked on June 27, 2016* -
## Physics

A 50 kg crate is initially at rest on a plane inclined at an angle of 30 degrees to the horizontal. A man then pulls the crate up the incline via a rope that is parallel to the inclined plane. The tension that the man imparts to the rope is 100 N, and the

*asked on November 1, 2010* -
## physics

A uniform plate of height = 1.80 m is cut in the form of a parabolic section. The lower boundary of the plate is defined by: = 1.20 . The plate has a mass of 1.29 kg. Find the moment of inertia of the plate about the y-axis.

*asked on March 19, 2008* -
## math

A street light is at the top of a 18 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 8 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 35 ft from the base of the pole?

*asked on March 25, 2008* -
## geometry

an A-frame house is 45 feet high and 32 feet wide. find the measure of the angle that the roof makes with the floor. Round to the nearest degree.

*asked on December 11, 2012* -
## geometry

A lot is in the shape of a trapezoid. The sum of the bases is 180 feet. If the area of the lot is 8,100 square feet, what is the distance across the lot, i.e., the altitude of the figure?

*asked on May 19, 2011* -
## Physics

A 50 kg crate is initially at rest on a plane inclined at an angle of 30 degrees to the horizontal. A man then pulls the crate up the incline via a rope that is parallel to the inclined plane. The tension that the man imparts to the rope is 100 N, and the

*asked on November 3, 2010* -
## Chem

Very hot zinc will react with steam to form zinc oxide and hydrogen. What volume of steam would be necessary in order to use up 20.0 g of zinc completely? What volume of hydrogen would be produced in this case? I NEED HELP WITH THIS!!..PLEASE = )

*asked on May 15, 2008* -
## Chemistry

Na₂CO₃ (s) + 2HCL (ag) → 2NaCl (ag) + CO₂ + H₂O (l) If 4.25g of sodium carbonate is reacted completely with excess hydrochloric acid as 3M HCl, how many mL of HCl would be consumed? Note: Assume 3M HCl contains 3.00 moles of HCl per liter of

*asked on April 30, 2012* -
## physics

A 12.0 g bullet is fired into a 13.9kg wooden block that is hanging straight down, suspended by a 2.00 m length of light line. The bullet has a muzzle velocity of 94.2 m/s. When the bullet hits the block, the bullet stays in the block. The block swings

*asked on March 15, 2014* -
## calculus

a particle moves along the x-axis (units in cm) its initial position at t=0 sec is x(0)=15. the figure shows the graph of the particle's velocity v(t). the numbers are areas of the enclosed regions. in the graph 0 to a is 4 under the x-axis, a to b is 5

*asked on April 28, 2010* -
## College Chemistry

Two moles of Mg and five moles of O2 are placed in a reaction vessel, and then the Mg is ignited to produce Mg (F.W.= 40.31 g/mole). What is the actual mole ratio, the calculated mole ratio, how many moles of MgO are formed, and what is the weight of MgO

*asked on October 21, 2012* -
## calculus

a lighthouse is 1 km from the shoreline and revolves at 10 pi radians a minute what is the speed of the light as it sweeps across the shore as it lights up at sand at 2 km from the light house

*asked on December 6, 2012* -
## Physics

The gravitational acceleration on the surface of Mercury is 0.38 times that of Earth. Its radius is also about 0.38 times that of the Earth. What is the ratio of the density of Mars to that of Earth?

*asked on December 5, 2013* -
## physics

A bus is moving at 30 m/s when the driver steps on the brakes and brings the bus to a stop in 2.6 s. What is the average acceleration of the bus while braking?

*asked on September 16, 2012* -
## Math

enrollment in a business seminar increased from 75 to 85 people. what is the persent increase

*asked on April 18, 2012* -
## math

Water is leaking out of an inverted conical tank at a rate of 11400 cm^3/min at the same time that water is being pumped into the tank at a constant rate. The tank has height 8.0m and the the diameter at the top is 3.5m. If the water level is rising at a

*asked on March 25, 2008* -
## physics

A particle moves along the axis under the influence of a variable force = 6.8x^2 + 4.4x where the force is measured in Newtons and the distance in meters. What is the potential energy associated with this force at = 4.0 m? Assume that = 0 J at = 0 m

*asked on March 4, 2008* -
## Math

i need help with the global convergence practice can someone please help?

*asked on October 25, 2018* -
## Physics

A horizontal rifle is fired at a bull's-eye. The muzzle speed of the bullet is 640 m/s. The gun is pointed directly at the center of the bull's-eye, but the bullet strikes the target 0.028 m below the center. What is the horizontal distance between the end

*asked on September 12, 2016* -
## Functions - more info

Sorry, I forgot to enter all the info before. Below is the updated info for the problem. What's the best way to solve functions? I can do basic ones, but have trouble with the harder ones. I'm having trouble with the following: Inputs x 1, 2, 3, 4, 5

*asked on May 22, 2012* -
## physics

A car (m = 1540 kg) is parked on a road that rises 18.9 ° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires?

*asked on February 19, 2012* -
## physics

The cable of an elevator of mass = 5320 kg snaps when the elevator is a rest at one of the floors of a skyscraper. At this point the elevator is a distance = 31.6 m above a cushioning spring whose spring constant is = 11700 N/m. A safety device clamps the

*asked on March 7, 2008* -
## Math

You are buying a fence to enclose a garden that has an area of 360 square feet. x + 9 The bottom of garden x side of garden a) What is the width of the area to be enclosed? Answer in units of ft b) How much fencing do you need? Answer in units of ft

*asked on January 28, 2015* -
## math

Jon begins jogging at a steady 3m/sec down the middle of lane one of a public track. Laura starts even with him in the center of lane two but moves 4m/sec. At the instant they begin, Ellie is located 100 meters down he track in lane four, and is heading

*asked on October 2, 2012* -
## maths

Using the digits 1, 2, 3 & 4 each once only, and as many +, -, x, / and brackets as you need, try to make as many different numbers as you can, starting at 0, 1, 2 .... Which is the first number that you cannot make? My answer is 3. Which is the largest

*asked on January 16, 2010* -
## language arts

What is it called when there are four periods at the end of a sentence? I know what it means but...

*asked on November 1, 2007* -
## Functions

What's the best way to solve functions? I can do basic ones, but have trouble with the harder ones. I'm having trouble with the following: Inputs x 1, 2, 3, ? Outputs y 0, 2, 6, ? I have tried everything and can't come up with the equation. Please help!

*asked on May 22, 2012* -
## physics

In a simple model of the wind speed associated with hurricane Emily, we assume there is calm eye 10.0 km in radius. The winds, which extend to a height of 5550 m, begin with a speed of 208.0 km/hr at the eye wall and decrease linearly with radial distance

*asked on March 17, 2008* -
## Physics

A bird watcher meanders through the woods, walking 1.13 km due east, 1.01 km due south, and 3.95 km in a direction 49.8 ° north of west. The time required for this trip is 1.965 h. Determine the magnitudes of the bird watcher's (a) displacement and (b)

*asked on September 12, 2016* -
## algebra

Steve's mon's age is 7 years less than 3 times Steve's age. The sum of their ages is 65 years. Find their ages.

*asked on December 2, 2010* -
## math..percents

Craig wants to buy some software for his computer. The company that makes the software sells it to a software distributor for $30. The distributor adds 15% to the price and then sells it to the store. The store adds 25% on top of the price they pay for it

*asked on June 16, 2006* -
## Physics

The captain of a plane wishes to proceed due west. The cruising speed of the plane is 255 m/s relative to the air. A weather report indicates that a 39.0-m/s wind is blowing from the south to the north. In what direction, measured with respect to due west,

*asked on September 12, 2016* -
## Science

It can be inferred from the passage that radioactive dating is important for estimating the age of A) all known meters B) all existing planets C) the earth D) the trees

*asked on August 11, 2016* -
## Physics

A particular asteroid has a circular orbit about the Sun with a radius of 450 million miles. How long does it take to go around the sun? Compare the prediction of Kepler's 2nd law to a direct computation with Newton's 2nd law. How much area does the line

*asked on December 5, 2013* -
## Physics

A car slows from 17 m/s to 2.0 m/s at a constant rate of 2.1 m/s2. How many seconds are required before the car is traveling at 2.0 m/s?

*asked on September 13, 2012* -
## physics

A golfer hits a shot to a green that is elevated 3.0 m above the point where the ball is struck. The ball leaves the club at a speed of 19.4 m/s at an angle of 45.0˚ above the horizontal. It rises to its maximum height and then falls down to the green.

*asked on February 18, 2012* -
## physics

The record for a marathon is 4 h, 36 min, 21 s. The marathon distance is 90.25 km. Determine the average speed in m/s of a runner achieving this record.

*asked on September 16, 2012* -
## physics

Which has the greater acceleration, a car that increases its speed from 50 to 62 km/h, or a bike that goes from 0 to 12 km/h in the same time?

*asked on September 16, 2012* -
## physics

pulsar is a rapidly rotating neutron star that emits radio pulses with precise synchronization, there being one such pulse for each rotation of the star. The period of rotation is found by measuring the time between pulses. At present, the pulsar in the

*asked on March 17, 2008* -
## physics

A particle moves along the axis under the influence of a variable force = 6.8 + 4.4 where the force is measured in Newtons and the distance in meters. What is the potential energy associated with this force at = 4.0 m? Assume that = 0 J at = 0 m

*asked on March 4, 2008*