Wednesday

April 23, 2014

April 23, 2014

Total # Posts: 66

**Physics**

A 1.25 kg skateboard is coasting along the pavement at a speed of 5.04 m/s when a 0.640 kg cat drops from a tree vertically downward onto the skateboard. What is the speed of the skateboard-cat combination? Answer in units of m/s Your answer must be within ± 1.0%

**Chemistry**

What mass of sodium benzoate should you add to 150.00 ml of a 0.15M benzoic acid solution to obtain a buffer with a pH of 4.25?

**Chemistry**

Calculate the ratio of NaF to HF required to create a buffer with a pH of 4.00.

**Pre-Calculus**

Well I need to graph it but it days I did it wrong. I don't know what to do with the 2 in front. I made a sign chart and got +,+,+,- and used the roots -2,0,5 and grape it but I think I'm making a mistake somewhere.

**Pre-Calculus**

Sketch the graph f(x)=-2x^2(x-5)^3(x+2)^4. What would be my coordinates. I solved it and my graph looks nothing like the one on wolframalpha. Can someone show me how you would solve this?

**Pre-Calculus**

Sketch the graph f(x)=-2x^2(x-5)^3(x+2)^4. What would be my coordinates. I solved it and my graph looks nothing like the one on wolframalpha. Can someone show me how you would solve this?

**Pre-Calculus**

Find a polynomial function with integer coefficients with degree 4, one root 3+radical2, and another root 4-3i. I got x^4-14x^3+80x^2-206x+175 I'm I correct?

**CHEM**

A 0.552 g sample of ascorbic acid(Vitamin C) was dissolved in water to a total volume of 20.0 ml and titrated with 0.1103 M KOH. The equivalence point occurred at 28.42 ml. The pH of the solution at 10.0 ml of added base was 3.72. From this data, determine the molar mass and K...

**math**

If there were only cats and dogs at the pound and the ratio of cats to dogs was 3:4 if there were 105 cats, how many animals altogether?

**Physics**

A parallel-plate capacitor is constructed with circular plates of radius 0.056 m. The plates are separated by 0.25 mm, and the space between the plates is filled with dielectric with dielectric constant k. When the charge on the capacitor is 1.2 uc the potential difference bet...

**Physics**

The electric flux through each of the six sides of a rectangular box are as follows: phi 1= +150.0 N*m^2/C; phi 2= +250.0 N*m^2/C; phi 3= -350.0 N*m^2/C; phi 4= +175.0 N*m^2/C; phi 5= -100.0 N*m^2/C; phi 6= +450.0 N*m^2/C How much charge is in this box?

**Physics**

A +5.0 uC charge experiences a 0.44 N force in the positive y direction. If this charge is replaced with a -2.7 uC charge, what force will it experience?

**Physics**

A uniform electric field of magnitude 2.70×10^4 N/C makes an angle of 37 degrees with a plane surface of area 1.60×10^−2 m^2 . What is the electric flux through this surface?

**Physics**

The electric field at the point x=5.00 cm and y=0 points in the positive x direction with a magnitude of 10.0 N/C. At the point x=10.0 cm and the electric field points in the positive x direction with a magnitude of 16.0 N/C . Assume this electric field is produced by a single...

**Physics**

An object with a charge of -4.4 uC and a mass of 1.4×10^−2 kg experiences an upward electric force, due to a uniform electric field, equal in magnitude to its weight. Find the magnitude of the electric field. Find the direction of the electric field. If the the ele...

**Physics**

Four point charges are located at the corners of a square with sides of length a . Two of the charges are +q, and two are -q. Find the magnitude of the net electric force exerted on a charge +Q, located at the center of the square, for the following arrangement of charge: the ...

**physics**

Two point charges, the first with a charge of +3.19×10^−6 C and the second with a charge of -4.32×10^−6 C , are separated by 28.0 cm. Find the magnitude of the electrostatic force experienced by the positive charge. Is the magnitude of the force experie...

**physics electricity & magnetism**

Charge Q=4 micro-coulombs is distributed uniformly over the volume of an insulating sphere of radius R=.05 meters. What is the potential difference between the center of the sphere and the surface of the sphere? How do I approach this problem? I tried integrating dV=-Edr from ...

**Physics**

Two ships in a heavy fog are blowing their horns, both of which produce sound with a frequency of 165.0 Hz One ship is at rest; the other moves on a straight line that passes through the one at rest. If people on the stationary ship hear a beat frequency of 3.5 Hz, what is the...

**Physics**

A pair of in-phase stereo speakers is placed side by side, 0.85 m apart. You stand directly in front of one of the speakers, 1.2 m from the speaker. What is the lowest frequency that will produce constructive interference at your location?

**Physics**

A motorcycle and a police car are moving toward one another. The police car emits sound with a frequency of 512 Hz and has a speed of 28.0 m/s. The motorcycle has a speed of 13.0 m/s. What frequency does the motorcyclist hear?

**Physics**

Write an expression for a transverse harmonic wave that has a wavelength of 2.8 m and propagates to the right with a speed of 14.2 m/s. The amplitude of the wave is 0.13 m, and its displacement at t=0 and x=0 is 0.13 m.

**Physics**

A ball rolls on a circular track of radius 0.65 m with a constant angular speed of 1.2 rad/s in the counterclockwise direction. Part A If the angular position of the ball at t= 0 is theta= 0, find the x component of the ball's position at the time 2.6 s. Let theta= 0 corre...

**Physics**

A mass attached to a spring oscillates with a period of 3.15 s. If the mass starts from rest at x= 4.10×10−2 m and time t= 0, where is it at time t= 6.37s? Is the mass moving in the positive or negative x direction at t= 6.37s?

**Physics**

A bunch of grapes is placed in a spring scale at a supermarket. The grapes oscillate up and down with a period of 0.41 s, and the spring in the scale has a force constant of 640 N/m. What is the mass of the grapes? What is the weight of the grapes?

**Physics**

When a 0.213-kg mass is attached to a vertical spring, it causes the spring to stretch a distance d. If the mass is now displaced slightly from equilibrium, it is found to make 150 oscillations in 52.0 s. Find the stretch distance, d.

**Physics**

Two people with a combined mass of 135 kg hop into an old car with worn-out shock absorbers. This causes the springs to compress by 9.80 cm. When the car hits a bump in the road, it oscillates up and down with a period of 1.76 s. Find the total load supported by the springs. F...

**Physics**

A vibrating structural beam in a spacecraft can cause problems if the frequency of vibration is fairly high. Even if the amplitude of vibration is only a fraction of a millimeter, the acceleration of the beam can be several times greater than the acceleration due to gravity. A...

**Physics**

A 0.55-kg air cart is attached to a spring and allowed to oscillate. If the displacement of the air cart from equilibrium is x=(10.0 cm)cos[(2.00 s ^-1)t + pi], find the maximum kinetic energy of the cart. Find the maximum force exerted on it by the spring.

**Physics**

The position of a mass oscillating on a spring is given by x=(4.7 cm)cos [2pi t/(0.52 s)]. What is the period of this motion? What is the first time the mass is at the position x=0?

**Physics**

Your heart beats with a frequency of 1.35 Hz. How many beats occur in a minute? If the frequency of your heartbeat increases, will the number of beats in a minute increase, decrease, or stay the same? How many beats occur in a minute if the frequency increases to 1.60 Hz?

**Physics**

A communications satellite with a mass of 450 kg is in a circular orbit about the Earth. The radius of the orbit is 2.9×10^4 km as measured from the center of the Earth. Calculate the weight of the satellite on the surface of the Earth Calculate the gravitational force e...

**Physics**

An equilateral triangle 10.0 m on a side has a 1.00-kg mass at one corner, a 2.00-kg mass at another corner, and a 3.00-kg mass at the third corner. Find the magnitude of the net force acting on the 1.00 kg- mass. Find the direction of the net force acting on the 1.00-kg mass....

**Physics**

An equilateral triangle 10.0 m on a side has a 1.00-kg mass at one corner, a 2.00-kg mass at another corner, and a 3.00-kg mass at the third corner. Find the magnitude of the net force acting on the 1.00 kg- mass. Find the direction of the net force acting on the 1.00-kg mass....

**Physics**

An astronaut exploring a distant solar system lands on an unnamed planet with a radius of 3800 km. When the astronaut jumps upward with an initial speed of 4.00 m/s , she rises to a height of 0.600 m. What is the mass of the planet?

**Physics**

Suppose a planet is discovered orbiting a distant star with 13 times the mass of the Earth and 1/13 its radius. How does the escape speed on this planet compare with that of the Earth? Ve new ------- = ve earth

**Physics**

Suppose one of the Global Positioning System satellites has a speed of 4.50 km/s at perigee and a speed of 3.52 km/s at apogee. If the distance from the center of the Earth to the satellite at perigee is 2.21×104 km, what is the corresponding distance at apogee?

**Physics**

Two 0.53-g basketballs, each with a radius of 17 cm, are just touching. How much energy is required to change the separation between the centers of the basketballs to 1.1 m? (Ignore any other gravitational interactions.) How much energy is required to change the separation bet...

**Physics**

The largest moon in the solar system is Ganymede, a moon of Jupiter. Ganymede orbits at a distance of 1.07 X 10^9 m from the center of Jupiter with an orbital period of about 6.18 X 10^5 s. Using this information, find the mass of Jupiter.

**Physics**

Gravity on Titan Titan is the largest moon of Saturn and the only moon in the solar system known to have a substantial atmosphere. Find the acceleration due to gravity on Titan's surface, given that its mass is 1.35 X 10^23 kg and its radius is 2570 km.

**Physics**

When the Earth, Moon, and Sun form a right triangle, with the Moon located at the right angle, the Moon is in its third-quarter phase. Find the magnitude of the net force exerted on the Sun. Find the direction of the net force exerted on the Sun. Give the direction relative to...

**Physics**

In each hand you hold a 0.15 kg apple. What is the gravitational force exerted by each apple on the other when their separation is 0.25 m? What is the gravitational force exerted by each apple on the other when their separation is 0.50 m?

**Physics**

A torque of 0.13 N*m is applied to an egg beater. If the egg beater starts at rest, what is its angular momentum after 0.50 s?

**Physics**

You pull downward with a force of 32 N on a rope that passes over a disk-shaped pulley of mass 1.3 kg and radius 0.075 m. The other end of the rope is attached to a 0.60 kg mass. Find the linear acceleration of the 0.60 kg mass.

**Physics**

A baseball bat balances 61.1 cm from one end. If a 0.600 kg glove is attached to that end, the balance point moves 22.7 cm toward the glove. Find the mass of the bat.

**Physics**

A uniform metal rod, with a mass of 3.0 kg and a length of 1.0 m, is attached to a wall by a hinge at its base. A horizontal wire bolted to the wall 0.64 m above the base of the rod holds the rod at an angle of 40 degrees above the horizontal. The wire is attached to the top o...

**Physics**

A set of fossilized triceratops footprints discovered in Texas show that the front and rear feet were 3.2 m apart. The rear footprints were observed to be twice as deep as the front footprints. Assuming that the rear feet pressed down on the ground with twice the force exerted...

**Physics**

A fish takes the bait and pulls on the line with a force of 2.2 N. The fishing reel, which has a friction clutch that exerts a restraining torque of 0.048 N m, is a cylinder of radius 0.055 m and mass 0.84 kg. Part A What is the angular acceleration of the fishing reel? B How ...

**chemistry**

Consider the reaction, C2H4(g) + H2(g) ® C2H6(g), where DH = – 137 kJ. How many kilojoules are released when 55.3 g of C2H4 reacts?

**reserch**

what changes would you half to make to a human being phisical features if it were to live in an enviroment with a temprature over 50c every day.

**math**

napoleon 1 was born in 1769 how old was he when he was crowned in france 1804 {equation]

**physics**

You want to nail a 1.5 kg board onto the wall of a barn. To position the board before nailing, you push it against the wall with a horizontal force F to keep it from sliding to the ground. (a) If the coefficient of static friction between the board and the wall is 0.71, what i...

**science**

The number of protons, neutrons and electrons, respectively, in 115Cd2+ are?

**science**

The number of protons, neutrons and electrons, respectively, in 115Cd2+ are?

**chemistry**

A 204.2 g sample of a mixture contains 22.3% sodium chloride. What mass (g) of sodium chloride is present in the sample

**chem**

no thats the whole question

**Math**

How many ways can 6 cars line up is it 6 X 6 is it 6 squared?

**chemistry**

An 8.00-gram sampleyields 1.64grams of Zinc when the compound is decomposed. What is the compound?

**chemistry**

HNO3 (g) + 4H2 (g) ---> NH3 (g) + 3H2O (g) deltaH = -637 kJ Calculate the enthalpy change when one mole of hydrogen reacts; and What is the enthalpy change when 10.00 g of ammonia is made to react with excess of steam to form nitric acid and hydrogen gases?

**chemistry- proofread n help**

all of the are correct except for CoSO4 is cobalt sulfate (SO4 is a Polyatomic ion

**chemistry**

HNO3 (g) + 4H2 (g) „³ NH3 (g) + 3H2O (g)deltaH = -637 kJ Calculate the enthalpy change when one mole of hydrogen reacts and What is the enthalpy change when 10.00 g of ammonia is made to react with excess of steam to form nitric acid and hydrogen gases?

**Physics.**

I posted at around 7:44 please help me, everytime I post, no one ever helps me, or it is too late...I only ever want physics help...so please, lend a helping brain! :) (Im not trying to come off mean, Im just frustrated beyond belief)

**English**

MANAGE!! :)

**Twelfth Grade Physics**

Just confused a little bit as to where to start. Can the 50 m also be the Range of the ball? And if that is so, can you use that to find v2, because the ball is falling at a constant of 9.81 m/s^2...and then you could say that Ryan runs the same velocity as the ball but in the...

**Twelfth Grade Physics**

A ball is kicked toward Ryan with an initial velocity of 21.0 m.s at an angle of 41 degrees above the horizontal. At that instant, Ryan is 51.0m from the kicker. In what direction, and with what constant velocity, should Ryan run in order to catch the ball at the level it was ...

**math**

at the beginning of the year, allison and sean togethor had 24 papergack books. during the year,allison doubled her supply but sean lost three of his. togethor they had 46 books at the end of the year. how many books did each have at the beginning of the year. You need to chec...

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