Friday

September 4, 2015
Total # Posts: 172

**Chimistry**

A piece of metal (75 g at 98.0°C) was dropped in water (95 g at 22.0°C) and the final temperature was measured to be 31.2°C. If the specific heat of water is 4.18 J/g°C. What is the heat capacity of the metal?
*May 18, 2015*

**physics**

(a) Find the electric potential difference V B − V A due to a point charge q 1 = −2.65 nC that is 0.250 m from location A and 0.410 m from location B. V (b) A charge q 2 moving from B to A gains in kinetic energy. What is the sign of this charge? positive negative
*April 1, 2015*

**physics**

Two charges q 1 = −3.20 nC and q2 = +8.96 nC are at a distance of 1.94 µm from each other. q 1 is fixed at its location while q 2 is released from rest. (a) What is the kinetic energy of the charge q 2 when it is 0.340 µm from q 1? J (b) The charge q 2 has a ...
*April 1, 2015*

**biology**

I have to write an essay on about why organ donation should be mandatory in Canada. I need help thinking of arguments. Some that I have thought of are: 1. there is a shortage of organs for transplants 2. it improves the life of the recipient 3. After death organs can be of use...
*April 1, 2015*

**physics**

A proton is acted on by an uniform electric field of magnitude 233 N/C pointing in the positive x direction. The particle is initially at rest. (a) In what direction will the charge move? (b) Determine the work done by the electric field when the particle has moved through a ...
*March 29, 2015*

**physics**

(a) A charged particle accelerates as it moves from location A to location B. If V A = 170 V and V B = 210 V, what is the sign of the charged particle? positive negative (b) A proton gains electric potential energy as it moves from point 1 to point 2. Which of the following is...
*March 29, 2015*

**physics**

Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the electric field strength between them, if the potential 8.50 cm from the zero volt plate (and 1.50 cm from the other) is 450 V? kV/m (b) What is the voltage ...
*March 29, 2015*

**physics**

An electron has an initial velocity of 2.00 ✕ 10 6 m/s in a uniform 6.00 ✕ 10 5 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? (b) How far does ...
*March 19, 2015*

**physics**

What is the magnitude and direction of an electric field that exerts a 4.00 ✕ 10 -5 N upward force on a - 1.80 µC charge? N/C
*March 16, 2015*

**physics**

Which of the following statements about electric field lines due to static charges are true? (Select all that apply.) Electric field lines can never cross each other. Static charges can create closed loop electric field lines that do not begin or end on a charge. Wider spacing...
*March 16, 2015*

**chemistry**

a) calculate the concentration of your unknown (Gatorade) using correct units Note if you did not run the Gatorade use absorbance =0.205 abs units in order to calculate the concentration of the dye in the Gatorade b) calculate of % T for an absorbance of 1.5 using the result. ...
*March 15, 2015*

**physics**

A solid, uniform disk of radius 0.250 m and mass 60.4 kg rolls down a ramp of length 4.60 m that makes an angle of 18.0° with the horizontal. The disk starts from rest from the top of the ramp. (a) Find the speed of the disk's center of mass when it reaches the bottom ...
*March 8, 2015*

**physics**

What is the force on the charge located at x = +8.00 cm in Figure 17.40(a) given that q = 5.00 n C and a = 7.00? (The positive direction is to the right.) N
*March 8, 2015*

**physics**

Guy has to get a piano onto a 2.4 m high platform. He can use a 3.0 m long frictionless ramp or a 4.0 m long frictionless ramp. Which ramp will Guy use if he wants to do the least amount of work? Either ramp as the work done is same in both cases. The shorter ramp will require...
*February 10, 2015*

**chemistry**

At 500 K in the presence of a copper surface, ethanol decomposesaccording to the following equation. C2H5OH(g) CH3CHO(g) + H2(g) The pressure of C2H5OH was measured as afunction of time and the following data were obtained. Time (s) PC2H5OH(torr) 0 250. 100. 237 200. 224 300. ...
*February 9, 2015*

**physics**

A 66-kg baseball player slides into third base. He starts his slide at a speed of 4.3 m/s and his speed is zero just as he reaches the base. If the coefficient of friction between his clothes and the surface of the baseball infield is 0.60, determine the following. (a) ...
*February 8, 2015*

**physics**

A baseball (m = 145 g) traveling 20 m/s moves a fielder's glove backward 25 cm when the ball is caught. What was the average force exerted by the ball on the glove? Magnitude N Direction in the direction opposite to the ball's motion in the direction of the ball's ...
*February 7, 2015*

**physics**

How much work must be done to stop a 1070 kg car traveling at 111 km/h?
*February 7, 2015*

**physics**

Thank you so very much
*February 3, 2015*

**physics**

Can the gravitational potential energy of a baseball ever be negative? Yes No Explain without using a formula.
*February 3, 2015*

**physics**

(e) If the speed of the ball at the bottom of the circle is v, what is the expression for the centripetal force on the ball in terms of its speed v and the length L of the string? Take the upward direction as positive and the downward direction as negative when considering ...
*January 25, 2015*

**physics**

The curves on a race track are banked to make it easier for cars to go around the curves at high speed. Draw a free-body diagram of a car on a banked curve. From the motion diagram, find the direction of the acceleration. The acceleration is directed toward the center of the ...
*January 20, 2015*

**physics**

A football is kicked from the ground with a speed of 23m/s at an angle of 42 degrees above the horizontal a) how long is the football in the air b) how far does it travel
*January 14, 2015*

**physics**

A quarterback threw a football at 27 m/s at a certain angle above the horizontal. If it took the ball 3.3 s to reach the top of its path, how long was it in the air? s
*January 13, 2015*

**physics**

A cargo plane is moving with a horizontal velocity of vx = +230 m/s at a height of y = 840 m above level ground as shown in the figure below when it releases a package. Ignoring air resistance, how much time will it take the package to reach the ground? (Express your answer to...
*January 12, 2015*

**math**

They are five apple slices in each school lunch. If 35 students buy a school lunch, hoe many apple slices are there ? Write an equation for this problem.
*January 5, 2015*

**physics**

Calculate the maximum deceleration of a car that is heading down a 14.5° slope (one that makes an angle of 14.5° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the ...
*December 15, 2014*

**physics**

Calculate the acceleration of a sled that is heading down a 50° slope (one that makes an angle of 50° with the horizontal). The coefficient of kinetic friction on ice is μk = 0.100. (Take the x direction to be parallel to and down the slope and the y direction to ...
*December 14, 2014*

**physics**

A skydiver weighing 840 N opens his parachute at the appropriate height from the ground. The air exerts a significant upward drag force, which is initially greater than the weight of the diver. This helps to slow the skydiver down. What is the diver's acceleration (both ...
*December 12, 2014*

**physics**

A 75 kg person escapes from the burning building by jumping from the window 25 m above a catching net air resistance exerts a 95 N force on the person during the fall apply Newton second law find the acceleration during the fall find the velocity and free body diagram
*December 11, 2014*

**physics**

A mover has to move a heavy sofa of mass 66 kg to the second floor of the house. As he pulls on the rope tied to the sofa he makes sure that the rope is parallel to the surface of the ramp, which is at 30.0° to the horizontal. If the coefficient of kinetic friction between...
*December 11, 2014*

**physics**

The stone was thrown through a distance of 80 cm the act of throwing takes approximately 0.064 s. determine the launch velocity of the stone
*December 9, 2014*

**physics**

A contestant in a winter games event pushes a 41.0 kg block of ice in the positive direction across a frozen lake as shown in the Figure (a). The coefficient of static friction is 0.1 and the coefficient of kinetic friction is 0.03.
*December 7, 2014*

**chemistry**

Sodium vapor lamps are used in Chicago to light city streets. The light emitted (given off) by these lamps has a λ of 5.9 x 10-7 m. What is the λ in cm? What is the λ in nanometers (nm) [1 meter = 1 x 109 nm]? What is the ν of this radiation? In what region...
*November 30, 2014*

**PROBATION AND PAROLE**

According to psychoanalytic theory, the unconscious: A. consists of thoughts and feelings that can easily be called into consciousness. B. is capable of strongly influencing conscious behavior. C. is considered by Freudian thought to develop during adolescence. D. does not ...
*November 20, 2014*

**chemistry**

A 18.3 g piece of aluminum (which has a molar heat capacity of 24.03 J/oC mol) is heated to 82.4oC and dropped into a calorimeter containing water (specific heat capacity of water is 4.18 J/goC) initially at 22.3oC. The final temperature of the water is 24.9oC. Calculate the ...
*November 18, 2014*

**physics**

An express subway train passes through an underground station. It enters at t = 0 with an initial velocity of 23.5 m/s and decelerates at a rate of 0.150 m/s2 as it goes through. The station in 215 m long. (a) How long is the nose of the train in the station? (b) How fast is ...
*November 17, 2014*

**physics**

On the moon, the acceleration due to gravity is only 1.6 m/s/s. If someone on earth can throw a baseball 24.2 m high, how high could he throw it on the moon?
*November 15, 2014*

**chemistry**

The reaction SO2 + H2O =H2SO4 Is the last step in the commercial production of sulfuric acid . the enthalpy change for this reaction is -227 KJ . In designing a sulfuric acid plant is it necessary to provide for heating or cooling of the reaction mixture ? explain
*November 12, 2014*

**physics**

A jet needs to reach a takeoff speed of 75.0 m/s. If the runway is 1625 meters long, what minimum acceleration is needed? How much time will it take to reach the takeoff speed
*November 6, 2014*

**physics**

while cruising along dark stretch of highway at a speed of 25 m/s you see that bridge ahead has been washed out. you apply the breaks to and come to a stop in 4.0 sec construct the position vs time graph and acceleration vs time graph and motion graph for 4 sec interval
*November 5, 2014*

**physics**

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the magnitudes of ...
*October 30, 2014*

**physics**

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the magnitudes of ...
*October 30, 2014*

**chemistry**

A 100 L flask contains a mixture of methane and argon gasses at 25 degree C . The mass of argon present is 228 g and the mole fraction of methane in the mixture is 0.650 . calculate the total kinetic energy of gaseous mixture
*October 26, 2014*

**chemistry**

A compressed gas cylinder contains 1.00 into 1000 g argon gas . the pressure inside the cylinder is 2050 psi at a temp of 18 degree . how much gas remains in the cylinder if the pressure is decreased to 650 psi at a temperature of 26 degree of 26 degree c
*October 26, 2014*

**chemistry**

A bicycle tire fitted was fitted with the air pressure of 75 psi at temperature 19 degree C riding the bike on a asphalt on a hot day increases temperature of the tire to 58 degree C. The volume increase by 4% . What is the new pressure
*October 26, 2014*

**Math**

45.43
*October 21, 2014*

**College Algebra (Word Problem)**

A rectangular eld is to be fenced o along the bank of a river; no fence is required along the bank of the river. The material for the fence costs 8 dollars per running foot for the two ends and 16 dollars per running foot for the side parallel to the river. If the area of...
*October 19, 2014*

**chemistry**

1) Aqueous solutions of potassium sulfate and ammonium nitrate are mixed together. Which statement is correct? A) Both KNO3 and NH4SO4 precipitate from solution B) A gas is released C) NH4SO4 will precipitate from solution D) KNO3 will precipitate from solution E) No reaction ...
*October 15, 2014*

**chemistry**

A beaker contain 300.ml of a 0,20 M Pb(NO3) solution. If 200 ml of 0,20M solution og MgCl2 is added to the beaker, What will be the concentration of Pb2+ ions in the resulting solution
*October 12, 2014*

**chemistry**

An unknown diprotic acid requires 26.66 mL of 0.117 M NaOH to completely neutralize a 0.845 g sample. what is the molar mass of the acid?
*October 12, 2014*

**chemistry**

A student weighs out 0.568 g of KHP (molar mass = 204 g/mol) and titrates to the equivalence point with 36.78 mL of a stock NaOH solution. What is the concentration of the stock NaOH solution? KHP is an acid with one acidic proton. a. 3.15 M b. 0.0757 M c. 0.943 M d. 0.100 M ...
*October 12, 2014*

**chemistry**

Thank you very much
*October 12, 2014*

**chemistry**

you have exposed electrodes of light bulb in a solution of H2SO4 such that the light bulb is on you add dilute solution and bulb goes dim which of the following could be the solution Ba(OH)2 NaNO3 K2SO4 Cu(NO3)2 none of the above
*October 12, 2014*

**chemistry**

An analytical procedure requires a solution of chloride ions ,How many grams of CaCl2 must be disolved to make2.15L of 0.0520 M C
*October 12, 2014*

**physics**

22) A golf ball moving forward with 1 unit of momentum strikes and bounces backward off a heavy bowling ball that is initially at rest and free to move. The bowling ball is set in motion with a momentum of A) less than 1 unit. B) more than 1 unit. C) 1 unit. D) not enough ...
*October 9, 2014*

**physics**

The x component of a displacement vector r is −149 m, while its y component is −174 m. (a) Find the magnitude of r. (b) Find the direction of r.
*October 7, 2014*

**chemistry**

n the spectroscopic analysis of many substances, a series of standard solutions of known concentration are measured to generate a calibration curve. How would you prepare standard solutions containing 10.0, 25.0, 50.0, 75.0, and 100. ppm of copper from a commercially produced ...
*October 6, 2014*

**chemistry**

Following oxidation-reduction reaction by using the oxidation state method a) O2+H2O+Pb=Pb(OH)2
*October 5, 2014*

**physics**

Thank you
*October 2, 2014*

**physics**

Drow a velocity time graph graph for the ball starting 1.0 s before the collision to wall and 1.0s after the collision
*October 2, 2014*

**physics**

Drow a velocity time graph graph for the ball starting 1.0 s before the collision to 1.0s after the collision
*October 2, 2014*

**chemistry**

A student mixes 4 reagents together thinking that the solution will neutralize each other . The solutions are mixed together are 50 ml of 0.100 M .hydrochloric acid 100 ml of 0.200 M of nitric acid 500 ml of 0.0100 M calcium hydroxide and 200 ml of 0.100 M of rubidium ...
*October 2, 2014*

**physics**

When a hammer strikes a nail, it is compressed along its length. Suppose that a steel nail 10.00 cm long and 3.00 mm in diameter is compressed an average of 65.0 µm by a 0.460 kg hammer during a 1.20 ms collision. (a) What average force was exerted on the nail by the ...
*October 1, 2014*

**physics**

A 0.450 kg hammer is moving horizontally at 6.00 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board. (a) Calculate the duration of the impact. (b) What was the average force exerted on the nail?
*October 1, 2014*

**physics**

One hazard of space travel is debris left by previous missions. There are several thousand masses large enough to detect by radar orbiting the earth, but there are far greater numbers of very small masses such as flakes of paint. Calculate the force exerted by a 0.150 mg chip ...
*October 1, 2014*

**chemistry**

A 30 ml sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration is 0.0300 M give some possible identities for the unknown base
*October 1, 2014*

**chemistry**

10 ml sample of vinegar an aqueous solution 0f acetic acid( HC2H3O2) is titrated with 0.5062 M and 16.58 ml is required to reach equivalence point what is the molarity of the acetic acid b. if the density of vinegar is 1.006 g/cm3 what is the mass percent of acetic acid of ...
*September 30, 2014*

**physics**

A 96.5 kg ice hockey player hits a 0.150 kg puck, giving the puck a velocity of 45.5 m/s. If both are initially at rest and if the ice is friction less, how far does the player recoil in the time it takes the puck to reach the goal 18.0 m away?
*September 29, 2014*

**physics**

A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.540 m/s. The total mass of the sled, man, and rock is 93.5 kg. The mass of the rock is 0.300 kg and the man can throw it with a speed of 15.0 m/s. Both speeds are ...
*September 29, 2014*

**physics**

Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48-kg skater acquires a speed of 0.65 m/s. If the other skater acquires a speed of 0.84 m/s, what is her mass?
*September 29, 2014*

**chemistry**

Balance following oxidation reduction reactions using oxidation states method? a) Cl2(g) + Al(s) --> Al3+(aq) + Cl- b.) O2(g) + H2O(l) + Pb(s) --> Pb(OH)2(s) c) H+(aq) + MnO4-(aq) + Fe2+(aq) --> Mn2+(aq) + Fe3+(aq) + H2O(l)
*September 28, 2014*

**chemistry**

Thank you I appreciate it
*September 27, 2014*

**chemistry**

the concentration of a certain sodium hydroxide solution was determined by using using the solution to titrate a sample of KHP is an acid with one acidic hydrogen and a molar mass of 204.22 g/mol. in the titration 34.67ml of the sodium hydroxide solution required to react with...
*September 27, 2014*

**chemistry**

30 ml of sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration 0.0300 M give the possible identities for the unknown base
*September 27, 2014*

**chemistry**

a student mixes 4 reagents together thinking that the solution will neutralize each other . The solution is mixed together are 50 ml of 0.100 M of HCL and 100 ml of 0,200 M of nitric acid 500 ml of 0.0100 M ca hydroxide and 200 ml of 0.100 M rubidium hydroxide . Did the acid ...
*September 27, 2014*

**physics**

Is momentum conserved when 2 carts having the same mass & the same speed collide, stick together and stop? what about the velocity
*September 25, 2014*

**chemistry**

what mass of silver chloride can be prepared by the reaction of 100 ml 0,20 M of silver nitrate with 100,0 ml of 0.15 M calcium chloride calculate the concentration of each ion reamaining in solution after the precipitation is complete
*September 24, 2014*

**ap chemistry**

what mass of barium sulfate can be produced when 100 ml 0.100 M of solution of barium chloride is mixed with 100.0 ml of a 0.100 M solution of Iron (III) sulfate
*September 24, 2014*

**ap chemistry**

what volume 0,100M of Na2PO4 is required to precipatate all the lead(II) ions from 150 ml of 0.250M Pb(NO3)2
*September 24, 2014*

**ap chemistry**

what volume of0.100 M NaPO4 is required to precipitate all the lead(II) ions from 150ml of 0.254 M Pb(NO3)2
*September 24, 2014*

**Math**

What does "Larger number exceeds three times the smaller number by four" mean?
*April 21, 2014*

**algebra**

Okay thanks, Marissa is my sister.
*November 20, 2013*

**algebra**

To the nearest tenth of an inch, find the length of a diagonal of a square whose side length is 8 inches.
*November 20, 2013*

**Calculus**

Consider the curve given by y^2 = 2+xy (a) show that dy/dx= y/(2y-x) (b) Find all points (x,y) on the curve where the line tangent to the curve has slope 1/2. (c) Show that there are now points (x,y) on the curve where the line tangent to the curve is horizontal. (d) Let x and...
*October 2, 2013*

**calculus**

Evaluate each of the following. Show all your calculations. f" (1/3) if f(x) = −2x^5 + 2x − 6
*April 17, 2013*

**calculus**

Evaluate each of the following. Show all your calculations. f" (1/3) if f(x) = −2x^5 + 2x − 6
*April 17, 2013*

**calculus**

Evaluate each of the following. Show all your calculations. f" (−3) if f(x) = 4x^3 − 3x^2 + 2x − 6
*April 17, 2013*

**calculus (gr 12)**

Evaluate each of the following. Show all your calculations. f′ (3/4)if f(x) = −3x^3 − 7x^2 + 4x − 11
*April 17, 2013*

**calculus (gr 12)**

Evaluate each of the following. Show all your calculations. f" (1) if f(X) = −3x^2 − 5x + 7
*April 17, 2013*

**calculus (gr 12)**

Evaluate each of the following. Show all your calculations. f' (−2) if f(x) = 2x^3 + 4x^2 − 5x + 8
*April 17, 2013*

**calculus (gr 12)**

Evaluate each of the following. Show all your calculations. f'(3) if f(x) = x^4 − 3x
*April 17, 2013*

**math**

thanks
*February 15, 2013*

**math**

Disks of radius 4 cm are cut from a rectangular plastic sheet of length 84 cm and width 24 cm. How many complete disks can be cut out? Find (a) the total area of the discs out (b) the area of sheet wasted I did it but the answers on the back of the book do not match heres what...
*February 15, 2013*

**math**

Julia and Bianca both leave the college at the same time, but in opposite directions. If Bianca travels 9 mph faster than Julia and after 4 hours they are 140 miles apart, how fast is each traveling?
*January 14, 2013*

**physics**

paul konerko hits a baseball in such a way that it leaves his bat traveling at 43.4m/s at an angle os 28 degrees above the horizontal when hit the baseball is 1.2 m above the ground 127 meter away is a 3.5 m tall fence iis this is home run
*September 21, 2012*

**Calculus**

I have no idea what to do with this problem. Please help me found the basic formula. When Apollo 15 astronaut David Scott dropped a hammer and a feather on the moon to demonstrate that in a vacuum all bodies fall with the same constant acceleration, he dropped them from about ...
*March 11, 2012*

**Physics **

A young woman named Kathy Kool buys a sports car that can accelerate at the rate of 4.77 m/s2. She decides to test the car by dragging with another speedster, Stan Speedy. Both start from rest, but experienced Stan leaves the starting line 1.04 s before Kathy. If Stan moves ...
*February 2, 2012*

**calculus**

Evaluate the integral from -4 to 4 of [x^3 sin(6x)] / [sin(5x)]dx
*December 10, 2011*

**Math**

If the value of $1 is 1.082431 in one year at 8 % compounded quarterly, what is the effective interest rate? (a)82.4% (b)8% (c)0.824% (d)8.24% (e)824.31%
*November 3, 2011*