# joy

Popular questions and responses by joy-
## physics

A 0.060 kg tennis ball, moving with a speed 2.50 m/s, collides head on with a 0.090kg ball initially moving away from it at a speed of 1.15 m/s. Assuming a perfectly elastic collision, what are the speed and direction of each ball after the collision?

*asked on August 19, 2010* -
## physics

The wave function (x,t)=(0.03m)sin(2.2x-3.5t) is for a harmonic wave on a string. (a) In what direction does this wave travel and what is its speed? (b) Find the wavelength, frequency, and period of this wave. (c) What is the maximum displacement of any

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

The figure below shows a box of dirty money (mass m1 = 4.0 kg) on a frictionless plane inclined at angle θ1 = 35°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.0 kg) on a frictionless plane inclined at angle

*asked on February 27, 2018* -
## Chemistry

Express the concentration of a 0.0510 M aqueous solution of fluoride, F-, in mass percentage and in parts per million. Assume the desnity of the solution is 1.00 g/mL Since, we're assuming the density I think that also means were assuming the volume.. but

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

3)A baseball player holds a 36oz bat (weight = 10N) with one hand at the point O (Figure below). The bat is in equilibrium. The weight of the bat acts along a line 60cm (or 0.6m) to the right of O. Determine the force and torque exerted on the bat by the

*asked on April 22, 2018* -
## math

A construction crew has just finished building a road. The road is 10 kilometers long. If the crew worked for 4 2/3 days, how many kilometers of road did they build each day? (Assume they built the same amount each day.) Write your answer as a mixed number

*asked on October 3, 2015* -
## english

When naval engagements occur they are carried on at such great---------- that the intervention of mist may obscure the contestants from each other 1 extremes ,2 risk , 3 ranges 4,pace, 5 disadvantegc

*asked on May 14, 2013* -
## physics

If α = 40°, β = 60°, and M = 4.0 kg, determine the tension in string 1 & 2. -------/ / 1 /2 / . . . Blockmass Alpha is on the top left angle and Beta is on the top right angle.

*asked on March 2, 2018* -
## physics

A solid cylinder of mass m and radius R rolls down a parabolic path PQR from height without slipping (assume R ≪ H) as shown in the figure below. Path PQ is rough (and so the cylinder will roll on that path), whereas path QR is smooth, or frictionless

*asked on April 14, 2018* -
## physics

The period of oscillation of a near-Earth satellite (neglecting atmospheric effects) is 84.3 min. What is the period of a near-Moon satellite? (R⊕= 6.37 × 10^6 m; RMoon= 1.74 × 10^6 m; m⊕ = 5.98 × 10^24 kg; mMoon = 7.36 × 10^22 kg.)

*asked on March 1, 2018* -
## maths

An ap has 15th and a common difference of -3 find the first and last term. If it. Sum is -120

*asked on October 12, 2016* -
## Physical science

which liquid evaporates fastest between water , ethanol , nail polish remover and methylated spirits

*asked on March 25, 2015* -
## Finance/Accounting

Milwaukee Surgical Supplies, Inc, sells on terms of 3/10, net 30. Gross sales for the year are $1,200,000 and the collections department estimates that 30 percent of the customers pay on the tenth day and take discounts, 40 percent pay on the thirtieth

*asked on October 2, 2008* -
## Mathematics

The angle of elevation of the top of a tower from a point 42m away from its base on level ground is 36.find the height of the tower

*asked on July 13, 2020* -
## math

The ratio of girls to boys in a school is 5:3. If there 60 boys, how many girls are in the school? I guessed it is 5+3=8.8/60

*asked on February 7, 2017* -
## physic

A golfer hits his approach shot at an angle of θ = 52.8°, giving the ball an initial speed of v0 = 37.0 m/s (see figure below). The ball lands on the elevated green, yf = 5.3 m above the initial position near the hole, and stops immediately. (a) How much

*asked on January 31, 2018* -
## Chemistry

A solution is made by mixing 42.0 mL of ethanol, C2H6O, and 58.0 mL of water. Assuming ideal behavior, what is the vapor pressure of the solution at 20 C in torr? Values at 20C ethanol density: 0.789 g/mL & vapor pressure (torr): 43.9 torr water: denisty:

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

Accoring to math teachers, what did the acorn say when it grew up? there is ten questions and 15 boxes

*asked on September 8, 2009* -
## Algebra

A company has determined that when x hundred dulcimers are built, the average cost per dulcimer can be estimated by C(x)=0.2x(squared)−2.6x+9.950, where C(x) is in hundreds of dollars. What is the minimum average cost per dulcimer and how

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

As in the figure below, a simple harmonic oscillator is attached to a rope of linear mass density 5.4 ✕ 10−2 kg/m, creating a standing transverse wave. There is a 4kg block hanging from the other end of the rope over a pulley. The oscillator has an

*asked on April 25, 2018* -
## math

booby cut a piece of wood into 3 pieces of the same length. after he cuts off 2 feet from one of the pieces, he is left with piece that is 5 feet long. what is the length of the piece of wood he started with?

*asked on June 28, 2016* -
## Solid Mensuration

The diagram is formed from 6 identical closed -packed circles. If the height of the figure is 2 feet, find the radius of each circle in inches.

*asked on April 30, 2016* -
## Mathematics

A T-bill with face value of $10,000 and 96 days to maturity is selling at a bank discount ask yield of 4.3%. A. What is the price of the bill? (use 360 days a year) B. what is its bond equivalent yield? A. .043 * (96/360) = .011 .011 * (1-.043) = $9,890 B.

*asked on August 23, 2013* -
## physic

Two blocks are connected by a rope that passes over a massless and frictionless pulley as shown in the figure below. Given that m1 = 18.04 kg and m2 = 10.57 kg, determine the magnitudes of the tension in the rope and the blocks' acceleration. T = N a =

*asked on February 5, 2018* -
## GEOMETRY MIDPOINT FORMULA steve how did this hapn

If a line is extended from A (2,3) through B ( -2, 0 ) to a point so that AC = 4ab Find the coordinates of C Please help thanks so much GEOMETRY MIDPOINT FORMULA - Steve, Thursday, January 30, 2014 at 11:58am B-A = (-4,-3) C-A = 4(B-A) = (-16,-12) C =

*asked on January 31, 2014* -
## Discrete Mathematics

Write the inverse, converse, and contrapositive of the following statement: upside down A x E R, if (x + 2)(x - 3) > 0, then x < -2 or x >3 Indicate which among the statement, its converse, ints inverse, and its contrapositive are true and which are false.

*asked on July 26, 2013* -
## mathematics

A triangle has sides 8 cm and 5 cm and an angle of 90 degrees between them. Calculate the smallest angle between them.

*asked on June 15, 2020* -
## physics

A uniform horizontal beam with a length of 8m and a weight of 200N is attached to a wall by a pin connection. Its far end is supported by a cable that makes an angle of 53° with the beam (Figure below). If a 600N person stands 2m from the wall, ﬁnd the

*asked on April 23, 2018* -
## physic

A circus performer stands on a platform and throws an apple from a height of 50 m above the ground with an initial velocity v0 as shown in the figure below. A second, blindfolded performer must catch the apple. If v0 = 21 m/s, how far from the end of the

*asked on January 30, 2018* -
## math

A student starts from A and walks 3km east to B, she then walk 5km on a bearing 152 degree from 13 . She reaches a point c . Find the distance and bearing of C from A.

*asked on May 25, 2017* -
## biology /check please

(stimulus v. response)? Which of the following is a stimulus, which is a response? Thanks 1)the recess bell ringing in an elementary school 2)your mouth watering at the sight of food on a plate 3)a sudden drop in air temperature 4) a flu virus entering

*asked on December 21, 2010* -
## physic

The figure below shows a box of dirty money (mass m1 = 4.0 kg) on a frictionless plane inclined at angle θ1 = 35°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.0 kg) on a frictionless plane inclined at angle

*asked on February 27, 2018* -
## physic

The Moon orbits Earth in a nearly circular orbit that lasts 27.32 days. Determine the distance from the surface of the Moon to the surface of Earth.

*asked on February 24, 2018* -
## physic

A circus performer throws an apple toward a hoop held by a performer on a platform (see figure below). The thrower aims for the hoop and throws with a speed of 22 m/s. At the exact moment the thrower releases the apple, the other performer drops the hoop.

*asked on February 1, 2018* -
## physic

A circus performer stands on a platform and throws an apple from a height of 49 m above the ground with an initial velocity v0 as shown in the figure below. A second, blindfolded performer must catch the apple. If v0 = 30 m/s, how far from the end of the

*asked on January 30, 2018* -
## Physics

A piece of copper ball of mass 20g at 200°c is placed in a copper calomiter of mass 60g containing 50g of water at 30°c ignoring heat losses.calculate the final steady temperature of the mixture

*asked on June 11, 2017* -
## Discrete Mathematics

Consider the following table of values for real valued functions f(x) and g(x). x 1 2 3 4 f(x) 3 1 4 2 g(x) 4 1 3 5 Find f o g(1) where o denotes function composition.

*asked on July 30, 2013* -
## Calculus

At time t = 0, a seed is planted. After t weeks, the height of the plant is given by f(t) = 0.3t² = 0.6t = 0.5 inches. At what rate is the plant growing after

*asked on May 13, 2013* -
## physics

A 4-m wooden platform weighing 160 N is suspended from the roof of a house by ropes attached to its ends. A painter weighing 640 N stands 1.2 m from the left-hand end of the platform. Find the tension in each of the ropes

*asked on March 3, 2012* -
## SCIENCE

I HAVE A DIAMOND BRACELET THAT HAS THE MARKINGS OF JAFA STAMPED ON THE INSIDE OF IT ABOVE 05TW MEANING THE TOTAL WEIGHT. WHAT DOES THE JAFA STAND FOR?

*asked on April 16, 2009* -
## physic

can somebody show me how to find the time s step by step. A golfer hits his approach shot at an angle of θ = 46.3°, giving the ball an initial speed of v0 = 39.6 m/s (see figure below). The ball lands on the elevated green, yf = 4.1 m above the initial

*asked on February 6, 2018* -
## physic

The figure shows the y-position (in blue) of a particle versus time. (a) What is the average velocity of the particle during the time interval t = 1.50 s to t = 4.50 s? (Express your answer in vector form.) Incorrect: Your answer is incorrect.

*asked on January 21, 2018* -
## Social Studies

What was the purpose of the Freedman's Bureau?

*asked on November 27, 2016* -
## Accounting

These questions are based on the following information and should be viewed as independent situations. Popper Co. acquired 80% of the common stock of Cocker Co. on January 1, 2009, when Cocker had the following stockholders' equity accounts. Common Stock-

*asked on August 13, 2013* -
## Discrete Mathematics

Let G be a graph with vertex set V = { v1, v2, v3, v4, v5}. Is it possible for the degrees of the vertices to be 3, 6, 2, 1, 5, respectively? Why or why not?

*asked on August 6, 2013* -
## Chemistry

if the mole fractionof sulfuric acid (H2SO4) in an aqueous solitioin is 0.325, what is the percent by mass of H2SO4?

*asked on March 3, 2013* -
## geometry

The surface area of a sphere is 64rr square centimeters. Find the radius.

*asked on May 24, 2011* -
## Chemistry

What is the mass of carbon dioxide if 100 grams of methane is oxidized to carbon dioxide and water?

*asked on April 28, 2011* -
## Chemistry

Any one there who would help me with my pr0blem!Please help me,tnx! What is the mass of carbon dioxide if 100 grams of methane is oxidized to carbon dioxide and water?

*asked on April 28, 2011* -
## Chemistry

What is the mass of carbon dioxide if 100 grams of methane is oxidized to carbon dioxide and water?

*asked on April 27, 2011* -
## 8th Grade Algebra-Answer Check

Write each decimal as a fraction in lowest terms. 1. 0.111... Answer: 1/9 2. 0.02 Answer: 1/50 3. 0.7272... Answer: 8/11 4. 0.012012... Answer: 4/333 ?? 5. 0.66666.... Answer: 2/3 6. 0.396 (reapeating sign over all numbers) Answer: 44/111 ??? If I got any

*asked on January 19, 2009* -
## Physics

How many days does it take for a perfect blackbody cube (0.0100m on a side, 30.0 degree C)to radiate the same amount of energy that a one-hundred-watt light bulb uses in one hour? I got no idea to do it. Please give me some hints!!!Thanks!!!

*asked on February 21, 2008* -
## Logic

DAD=18, FISH=84, FEED=40, what is BEACH?

*asked on May 20, 2020* -
## Math

The value of a car purchased for $28,000 decreases at a rate of 9% per year. What will be the value of the car after 7 years? ( round to the nearest tenth)

*asked on April 5, 2020* -
## Math

An arc of lenght 28m subtends an angle of 24 at the centre of a circle.In the same circle,what angles does an arc of lenght 35m subtend?

*asked on June 13, 2019* -
## physics

An electric motor exerts a constant torque of 10N⋅m to the shaft of a grindstone with mass 16kg and radius 0.5m. If the system starts from rest, find (a) the rotational kinetic energy of the grindstone after 8s, (b) the work done by the motor during this

*asked on April 22, 2018* -
## physics

A 0.410-kg soccer ball is kicked at an initial speed of 32.5 m/s at an angle of 33.0° to the horizontal. What is the kinetic energy of the soccer ball when it has reached the apex of its trajectory?

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

A block with mass m1 hangs from a rope that is extended over an ideal pulley and attached to a second block with mass m2 that sits on a ledge. The second block is also connected to a third block with mass m3 by a second rope that hangs over a second ideal

*asked on February 7, 2018* -
## physic

A circus performer throws an apple toward a hoop held by a performer on a platform (see figure below). The thrower aims for the hoop and throws with a speed of 28 m/s. At the exact moment the thrower releases the apple, the other performer drops the hoop.

*asked on January 30, 2018* -
## physic

Tadeh launches a model rocket straight up from his backyard that takes 6.96 s to reach its maximum altitude. (After launch, the rocket's motion is only influenced by gravity. Enter magnitudes only.) (a) What is the rocket's initial velocity? m/s (b) What

*asked on January 24, 2018* -
## Math

A paper cone has a base diameter of 8cm and a height of 3cm(a) use Pythagoras theorem to calculate it's slant height (b)if the cone is cut and opened out into the sector of a circle what is the angel of the sector

*asked on May 30, 2016* -
## Accounting

Genentech, Inc. is a California-based biotech pioneer recently acquired by Swiss pharmaceutical giant Roche Holding AG. Roche paid $46.8 billion in cash for the 44 percent of Genentech it did not already own, implying a market value of over $100 billion

*asked on November 2, 2013* -
## biology /check please

Is this true or false? 1. Ideas about the value of knowledge gained through scientific research come from a society's social, ethical, and moral concerns. 2. Pure science is scientific research carried out primarily to solve specific environmental problem.

*asked on December 23, 2010* -
## Physics

A car is traveling around a horizontal circular track with radius r = 240 m at a constant speed v = 25 m/s as shown. The angle èA = 34° above the x axis, and the angle èB = 65° below the x axis. I found the car's acceleration to be 2.6 m/s^2 (a=v^2/r).

*asked on September 11, 2010* -
## physics

[20 pts] A 2.00 kg block is pushed against a spring with negligible mass and force constant k = 400 N/m, compressing it 0.220 m. When the block is released, it moves along a frictionless, horizontal surface and then up a frictionless incline with slope 37

*asked on August 19, 2010* -
## Physics

1. How does the back wheel of a bicycle turn if the torque of the chain/gear is applied at the center of the wheel? 2. In a real bicycle, the normal force on the front wheel from the ground acts slightly away from the vertical line passing through its

*asked on May 11, 2020* -
## Chemistry

What volume of distilled water should be added to 400cm3 of 2.0mol/dm 3 H2SO4 to obtain 0.20mol/dm3 of solution

*asked on August 2, 2018* -
## physics

A physical pendulum in the form of a thin rod of length 1.04 m is pivoted at point P, a distance x from the pendulum's center of mass. Find the value of x for which the period of the pendulum will be a minimum.

*asked on April 25, 2018* -
## physics

A simple harmonic oscillator's velocity is given by vy(t) = (0.86 m/s)sin(11t − 5.55). Find the oscillator's position, velocity, and acceleration at each of the following times. (Include the sign of the value in your answer) a) t = 0s b) t = 0.5s c) t =

*asked on April 24, 2018* -
## physics

In each situation shown in the figure below, a ball moves from point A to point B. Use the following data to find the change in the gravitational potential energy in each case. You can assume that the radius of the ball is negligible. (a) h = 1.45 m, θ =

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

In the figure below, 5.2 kg block A and 6.2 kg block B are connected by a string of negligible mass. Force A = (16 N) acts on block A; force B = (27 N) acts on block B. What is the tension in the string? (Express your answer in vector form.) To see the

*asked on February 26, 2018* -
## physics

A race car travels 40 m/s around a banked (45° with the horizontal) circular (radius = 0.20 km) track. What is the magnitude of the resultant force on the 80-kg driver of this car?

*asked on February 26, 2018* -
## physic

Somebody please show me how to get to the answer key for this question.I have been stuck at this question for days. Two black holes (the remains of exploded stars), separated by a distance of 10.0 AU(1 AU = 1.50 ✕ 10^11 m), attract one another with a

*asked on February 23, 2018* -
## physic

Two spheres of mass M1 = 810 kg and M2 = 390 kg are placed 4.80 m apart. A particle of mass m = 12.0 kg is now placed midway between the two spheres. (a) What is the net gravitational force on the particle due to the two spheres? N toward the sphere of M1

*asked on February 21, 2018* -
## physics

A sled and rider have a total mass of 58.4 kg. They are on a snowy hill accelerating at 0.4g. The coefficient of kinetic friction between the sled and the snow is 0.17. What is the angle of the hill's slope measured upward from the horizontal? You may find

*asked on February 12, 2018* -
## physic

A particle with mass m = 3.80 kg accelerates according to a = (−2.60i + 1.70j) m/s2. (a) What is the net force acting on the particle? (Express your answer in vector form.) F = N (b) What is the magnitude of this force? N

*asked on February 5, 2018* -
## physic

A race car travels 950 km around a circular sprint track of radius 1.343 km. How many times did it go around the track?

*asked on January 19, 2018* -
## Physics

Calculate the heat energy needed to change the temperature of 2 kg of copper from 10°C to 110°C. I forgot the formula

*asked on January 15, 2018* -
## Maths

There are m boys and 12 girls in a class what is the probability of selecting of random 1 a girl 2 a boy from class

*asked on January 29, 2017* -
## Word problems

I have some money, I spend half at the bookshop, a quarter at the supermarket and an eighth on sweets. I have £3.25 left.how much did I have to start with

*asked on October 6, 2016* -
## SCIENCE

A BOX HAS A BASE SURFACE AREA OF25cm2 AND THE WEIGHT OF 100N.CALCULATE THE PRESSURE IT EXERTS ON THE GROUND.

*asked on May 14, 2016* -
## SCIENCE

A MACHINE OF EFFICIENCY 60% IS USED TO RAISE A LOAD OF 150kg THROUGH A VERTICAL DISTANCE OF 2.5m.CALCULATE THE WORK DONE [IN JOULES]. I tried E=WORK OUTUT/WORK INPUT times 100% 60=150 times 10 times 2.5/work input times 100 60 times work input=3750 times

*asked on January 31, 2016* -
## Advanced MicroEconomics

Construct a short-run supply function for a firm whose short-run cost function is C= = 0.04q^3 – 0.8q^2 +10q+5 3. The long run cost function for each firm is C = q^3 – 4q^2 + 8q. Find the industry’s long run supply curve. If the market demand curve

*asked on November 12, 2013* -
## Partial Differential Equations

At the He-Ne laser wavelength (L= 632.8 nm) the refractive indices of crystal quartz are n o = 1.54264 and n e = 1.55171 calculated from its Sellmeier equation. The laser is incident from the air onto the surface of crystal quartz at an angle of incidence

*asked on November 12, 2013* -
## Mathematics

Anna burned 15 calories per minute running for x minutes and 10 calories per minute hiking for y minutes. She spent a total of 60 minutes running and hiking and burned 700 calories. The system of equations shown below can be used to determine how much time

*asked on September 24, 2013* -
## Accounting

These questions are based on the following information and should be viewed as independent situations. Popper Co. acquired 80% of the common stock of Cocker Co. on January 1, 2009, when Cocker had the following stockholders' equity accounts. Common Stock-

*asked on August 13, 2013* -
## Discrete Mathematics

16. What is the value of a that would make the matrix equation true?: ( 1 -2) (-5 6) (a b) ( 3 4) (7 -8) = (c d)

*asked on July 30, 2013* -
## Discrete Mathematics

You borrow $100,000 for a conventional 30 year mortgage at a 4% interest rate. Which is the first year, where years are 1-30, where you will pay more principal than interest?

*asked on July 30, 2013* -
## U.S/history AP

--------During french and Britsh fighting Washington declared that U.S.would not choose sides even though Hamilton wanted to support the British and Jefferson the French due to the FRANCO-AMERICAN ALLIANCE. my answer Treaty of Alliance

*asked on April 15, 2013* -
## Chemistry

Is my answer correct? 25g/2.5cm^3 equals 1g/cm^3

*asked on September 10, 2012* -
## Algebra II

Solve for x. ln (x + 2) - ln 36 = ln x

*asked on November 21, 2011* -
## geometry

WHAT IS THE LATERAL AREA FORMULA FOR A TRAPEZOID PRISM

*asked on May 14, 2011* -
## chemistry/HELP PLLEASE

can someone please help me balance this equation?: potassium permanganate reacts with iron(II)sulfate and sulfuric acid to produce iron(II)sulfate and manganese(II)sulfate and potassium sulfate and water

*asked on February 18, 2011* -
## biology can someone check

Identify each of the parentheses items as an independent or dependent variable. 1)The (number of red blood cells )independent in a mouse's blood at(different levels of iron) dependent in its diet. 20)The (amount of starch formed)dependent in a plant leaf

*asked on December 28, 2010* -
## Physics

A standing wave moves back and forth in a 150 cm long container with a frequency of 0.3 HZ. What is the velocity of the wave?

*asked on September 16, 2010* -
## physics

A 0.25 kg skeet (clay target) is fired at an angle of 30 degrees to the horizon with a speed of 25 m/s. When it reaches the maximum height, it is hit from below by a 15 g pellet travelling upward at a speed of 200 m/s. The pellet is embedded in the skeet.

*asked on August 19, 2010* -
## Math

A 24-cm segment is divided into two segments. One segment is three times as long as the other. Find the lenghts of both segments.

*asked on September 28, 2009* -
## Marketing

Preparating ground for new product

*asked on June 3, 2016* -
## Chemistry

What is wrong with the names 2-ethyl-4 and 4-dimethylpentane?

*asked on September 3, 2012* -
## Chemistry

Mr.drwls help me to check if my answer is c0rrect,tnx anyways, what is the mass of calcium carbonate is required to react with sulfur dioxide produced by burning 1000 kgs of coal that contain 5% sulfur by mass? (0.781 kmole)(100kg/mole)=78.1 kg

*asked on April 28, 2011*