# Posts by DANNY

Total # Posts: 867

Physics
A baseball player with a mass of 79 kg slides into homeplate. The coefficient of kinetic friction between the player and the ground is μk = 0.632. If the player comes to rest after 1.04 s, what is his initial speed?

Calculus Physics
help anyone

Calculus Physics
Imagine a spaceship on its way to the moon from the earth. Find the point, as measured from the center of the earth, where the force of gravity due to the earth is balanced exactly by the gravity of the moon. This point lies on a line between the centers of the earth and the ...

Calculus Physics
A glass of orange juice is on the floor of a subway car traveling along a straight path at constant velocity. Everything's fine. The coefficient of static friction between the glass and the floor is 0.32. The subway suddenly accelerates forward. What is the maximum ...

chemistry
One of the ways to produce iron is to take iron(II) oxide and react it with carbon monoxide to get pure iron and carbon dioxide. The reaction is FeO(s) + CO(g) = Fe(s) + CO2(g). What is the partial pressure of CO2(g) if 2.00 atm of CO and excess iron(II) oxide are used to ...

chemistry
Lead iodide is a relatively insoluble compound. It can dissolve from the solid phase into the aqueous phase with a Keq of 0.00027. If the concentration of lead iodide in the aqueous phase 0.125 M, then: a. we need more information to determine the progress of the reaction. b. ...

chemistry
Equilibrium is: a dynamic condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the rate of ...

Science check
Water in the upper zones of the ocean will have more oxygen than water in deeper zones. true or false i think true.

math
6528

physics
PART ONE: A charge of 4.70μC is at the origin and a second charge of −2.85μC is on the positive x-axis 1.08 m from the origin. Find the magnitude of the electric field at a point P on the y-axis 0.640 m from the origin. The value of the Coulomb constant is 8.99...

chemistry
increase the temperature ?

chemistry
The following equilibrium exists in a closed container: N2(g) + O2(g) = 2NO(g), ΔH = +181 kJ/mol. Which of the following perturbations would favor the formation of NO(g)? (practice MCAT question from The Princeton Review MCAT Science Workbook, 2009 edition) increasing the...

chemistry
Suppose you have the following reaction at equilibrium: N2(g) + 3H2(g) = 2NH3(g), ΔH = −22 kcal/mol What changes are expected to occur if the temperature of the system was decreased. You may select multiple answers. The concentration of NH3(g) would decrease The ...

chemistry
1) C2H2O4(aq) = H+ (aq) + C2HO4- (aq); Keq = 6.5E-2 2) C2O42- (aq) + H+ (aq) = C2HO4- (aq); Keq = 1.64E+4 then what is the equilibrium constant for the following reaction: C2H2O4(aq) = 2H+ (aq) + C2O42- (aq)? Keq = 1070 Keq = 227 Keq = 2.21E-4 Keq = 3.96E-6 Keq = 6.30E-3

chemistry
The pollutant NO is formed in diesel engines. The reaction fixes atmospheric nitrogen with oxygen to form NO. The reaction is: N2(g) + O2(g) = 2NO(g). If the equilibrium constant for this reaction at elevated temperatures is 5.60E-11, then what is the partial pressure of NO ...

chemistry
How is the reaction quotient used to determine whether a system is at equilibrium? The reaction is at equilibrium when Q > Keq. At equilibrium, the reaction quotient is undefined. The reaction quotient must be satisfied for equilibrium to be achieved. The reaction is at ...

chemistry
Which of the following statements is not true? 1.Chemical equilibria are examples of reversible processes. 2.When multiple reaction steps are in equilibrium, then the equilibrium constant for the net reaction is the product of the individual reactions. 3.The equilibrium ...

Calculus Physics
Nevermind I figured it out

Calculus Physics
A 1559-kg car moves at 15.0 m/s. What is the magnitude of the horizontal net force needed to bring the car to a halt in a distance of 50.0 m?

Calculus Physics
Thanks Steve

Calculus Physics
That's F(t)=5sqrt(t)

Calculus Physics
A particle is subject to a time-dependent force: F(t)=5t√. If the particle's mass is 7 kg, what will its velocity be at t=6.7 seconds, assuming its initial velocity at t=0 is equal to 0.

Calculus Physics
A particles with mass 3.7 kg moves in the x direction according to the following function: x(t)=−7+4t+3t2−4t3. (the units of each coefficient are meters, and time is measured in seconds). At time t=7.8, what is the net force acting on the particle?

Calculus Physics
A box and one force vector, F1 is shown. F1 = + 10 N. If the mass of the box is 3 kg, what is the magnitude and direction of a force, F2, that would need to be applied if the box was to have an acceleration of + 2 m/s 2 in the horizontal direction. (Indicate direction by ...

physics
38. A rock of mass 0.400 kg is released from the surface and sinks in the ocean. As the rock descends it is acted upon by three forces: gravity, buoyancy, and drag. The buoyancy is an upward force equal to half its weight. Drag from the water can be modeled by F = kv, where k...

physics
21. A traffic signal of mass 25.0 kg is suspended by two cables as shown in the diagram below. Solve for the tension in each cable each of the following scenarios: (a) θ1 = θ2 = 20.0°, and (b) θ1 = 20.0°, θ2 = 30.0°.

chemistry
Two-stroke motor boat engines emit a large amount of partially burned fuel into the water. One of the more common chemicals is phenanthrene . The degradation half-life of phenanthrene is about 7.30 days in clear surface waters. If a motor boat emits 97.0 g of phenanthrene ...

chemistry
Based on reaction kinetics, which of the following pairs of reactions and reaction rate equations represent elementary reactions? You may choose more than one reaction. Ti + 2Cl2 = TiCl4 Rate = k[Ti][Cl2] 2SO2 + O2 = 2SO3 Rate = k[O2][SO2]2 Na2S + CuSO4 = CuS + Na2SO4 Rate = k...

chemistry
The activation energy of a reaction is typically determined by calculating the rate constant for the reaction at two temperatures and then manipulating the Arrhenius equation. If you determine the reaction rate constants for a particular reaction to be 0.0650 /s at 25.0 C and ...

chemistry
Suppose 100 moles of a chemical is spilled into a lake. After 15.0 days, the total amount of the chemical in the lake 3.50 moles. Assuming that the reaction followed first order kinetics and no chemical was lost due to advection or volatilization, then what is the rate ...

chemistry
Radioactive waste is difficult to dispose of due to the long time periods needed before the radiation effectively disappears. The US protocol is to store the waste for 10 half-lives of the material after which the waste is no longer considered radioactive. After this time, ...

chemistry
In which of the following reactions is ΔE closest in value to ΔH? HNO3(aq) + Na2(CO3)(aq) = NaNO3(aq) + H2O(l) + CO2(g) KClO3(s) = KCl(s) + (3/2)O2(g) HCl(aq) + NaOH(aq) = H2O(l) + NaCl(aq) Na(s) + H2O(l) = NaOH(aq) + (1/2)H2(g)

chemistry
If the breakdown half-life of a pesticide applied to a farmer’s field is 3.50 days, then what is the rate constant for this reaction? Assume the degradation reaction follows first order kinetics. The units are 1/d.

chemistry
Ethylene gas (C2H2) can be formed from the reaction of calcium carbide (CaC2) with water. What is the reaction rate if 14.2 grams of ethylene gas are produced over 4.00 seconds? The units are mol/s.

Language Arts
Yup answers are B A C D B

physics
REALLY NEED HELP WITH THIS PLEASE. One gram of palladium has 5.66×10^21 atoms, and each palladium atom has 46 electrons. How many electrons are contained in 7.00g of palladium? The elemental charge is1.6×10^−19C. Answer in units of electrons. The answer is 1....

physics
One gram of palladium has 5.66×10^21 atoms, and each palladium atom has 46 electrons. How many electrons are contained in 7.00g of palladium? The elemental charge is1.6×10^−19C. Answer in units of electrons. The answer is 1.82252x10^24 for Part A. i need help...

Physics
no the answer is incorrect. im so confused @bob

Physics
One gram of palladium has 5.66×10^21 atoms, and each palladium atom has 46 electrons. How many electrons are contained in 7.00g of palladium? The elemental charge is1.6×10^−19C. Answer in units of electrons. The answer is 1.82252x10^24 for Part A. i need help...

chemistry
Calculate the change in Gibb’s free energy when 1.63 moles of sodium metal react with excess chlorine gas to form sodium chloride . Assume standard conditions. The ΔG values can be found in your textbook. The units for the answer are kJ

chemistry
White phosphorus (P4) was used for a long time in military incendiary bombs and ordnances. White phosphorus reacts with oxygen in the air and burns at very high temperatures, so it sets things on fire. Calculate the change in enthalpy resulting from a 25.0 pound white ...

chemistry
Calculate the change in free energy when you drop 4.70 g of calcium metal into a beaker containing excess water so that Ca(OH)2(s) and H2 gas are formed? The delta-G values you need are in your textbook. The units are kJ.

chemistry
Which of the following processes is entropy increasing in the local system? You may select multiple processes. Combination reactions where two reactants join to make a single product. a system with increasing molecular motion cooling a six-pack of beer by putting it in a ...

chemistry
Which of the following reactions will be spontaneous at standard state? Not all the reactions are balanced, so make sure they are balanced first. The ΔG of formation data can be found in an appendix in your text book. You may select multiple answers. Any reaction with ...

chemistry
ΔS is positive for which one of the following reactions? Ag+(aq) + Cl- (aq) = AgCl(s) N2(g) + 3H2(g) = 2NH3(g) CaO(s) + CO2(g) = CaCO3(s) 2SO3(g) = 2SO2(g) + O2(g) H2O(l) = H2O(s)

chemistry
Suppose you have a reaction that has a ΔH of +80 kJ and a ΔS of 215 J/K. At what temperature will this reaction change from being not spontaneous to spontaneous? 31 C 99 C -18 C 25 C 53 C

Physics
huihillll

chemistry
Given the following values of ΔH, ΔS and T, calculate ΔG (in kJ). The values are: ΔH = 23.0 kJ, ΔS = 125 J/K, and temperature = 85.0 C.

chemistry
Given the following values of ΔH, ΔS and T, calculate ΔG (in kJ). The values are: ΔH = -95.0 kJ, ΔS = 217 J/K, and temperature = 160 C.

chemistry
How many core electrons are there in a ground state phosphorus atom?

chemistry
Given: Equation #1: 4NH3(g) + 5O2(g) = 4NO(g) + 6H2O; ΔH of reaction = -1170 kJ Equation #2: 4NH3(g) + 3O2(g) = 2N2(g) + 6H2O; ΔH of reaction = -1530 kJ Then what is the ΔH of reaction for: N2(g) + O2(g) = 2NO(g)? Enter a numerical value below and be sure to ...

chemistry
Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) gas and calcium hydroxide (Ca(OH)2). If the ΔH for: CaC2(s) + 2H2O(l) = Ca(OH)2(s) + C2H2(g) is -127 kJ, then what is the enthalpy of formation for calcium carbide? The ΔH of formation for H2O(l), Ca(...

chemistry
Suppose that your morning shower is 7 minutes long and uses 4 gallons of water per minute that is a nice 102 F in temperature. How much energy (kJ) must be used to heat the water for your shower if the water coming into your house is at 60 F? The heat capacity of water is 4....

chemistry
Suppose you add 92 ml of dilute acid to 46 ml of water. Both the water and acid were at room temperature (22 C) before being mixed. The temperature of the solution increased to 39 C. How much energy (in kJ) was released by the dissolution of the acid if the specific heat ...

chemistry
In the reaction below, ΔH°f is zero for ___________. Ni(s) + 2CO(g) + 2PF3(g) = Ni(CO)2(PF3)2(l) Ni(s) CO(g) Ni(CO)2(PF3)2(l) both CO(g) and PF3(g) PF3(g)

chemistry
The enthalpy change for the following reaction is -483.6 kJ: 2H2(g) + O2(g) = 2H2O(g) Therefore, the enthalpy change for the following reaction is _______ kJ: 4H2(g) + 2O2(g) = 4H2O(g)

chemistry
What is the specific heat capacity of ethanol (C 2H 6O) if a 18.3 g sample increased 12.3 C upon the addition of 553.0 J? The units are J/(g ·K)

chemistry
The radiator in your car uses either water or ethylene glycol (anti-freeze) to remove heat from the engine and dissipate it to the outside air. If the water recirculation rate is 17.0 kg per minute of water and the water temperature leaving the engine and entering the ...

chem
What is the specific heat capacity of aluminum if a 8.4 g sample increased 21.1 C upon the addition of 159.0 J? The units are J/(g ·K). q=cpxMxT is the equation my answer i got is 401.65 is that right bec i feel that's wrong

chemistry 116
What is the specific heat capacity of aluminum if a 8.4 g sample increased 21.1 C upon the addition of 159.0 J? The units are J/(g ·K). q=cpxMxT is the equation my answer i got is 401.65 is that right bec i feel that's wrong

chem
The value for ΔH° for the reaction below is -72 kJ. How many kJ of heat are released when 1.0 mol of HBr is formed in this reaction? H2(g) + Br2(l) = 2HBr(g)

physics
What is the mass of 5.00L of pure water?

Math.
Guys, I am a witness to kid and Summer Moriarty telling you guys the wrong answers. The answers to this quick check 1.B 2.D 3.A 4.C 5.C I got a 100% on this quiz. Anonymous is right when he/she says it's B and D. The answer to number 2 is not A. Don't listen to Summer ...

physics
A typical multivitamin tablet can contain 2.00mg of vitamin B2 (riboflavin), and the RDA is 0.0030 g/day. How many such tablets should a person take each day to get the proper amount of this vitamin, assuming that he gets none from any other sources?

chemistry 116
The thermite reaction demonstrated in class requires high temperatures to start the reaction. A simple open flame is not enough to start the reaction. Once the reaction is going, then it generates enough heat to keep the reaction going. According to the literature on thermite...

chemistry 116
A 36.0 g piece of copper at 130.0 C is placed in 50.0 g of water at 20.0 C. What is the temperature (in C) of the water once the system reaches equilibrium? The molar heat capacity of copper is 24.5 J/(mol·K). The specific heat capacity of water is 4.18 J/(g·K...

chem
so i did 17000 x4.18x(86-46)=284 is that what you meant

chem
The radiator in your car uses either water or ethylene glycol (anti-freeze) to remove heat from the engine and dissipate it to the outside air. If the water recirculation rate is 17.0 kg per minute of water and the water temperature leaving the engine and entering the ...

chem
thank you i got 801.1678 is that correct

chem
If you burn 13.7 g of methane (CH4) burns in oxygen, then 686 kJ is evolved. What is the amount of heat produced per mole of methane burned?

chem
Suppose you mix hydrogen, CCl4, CO2, NO2 and fluorine gases together and allow them to reach an equilibrium temperature. Which gas has the SLOWEST average molecular (or atomic) speed?

LA
Hey everyone I just took this and the first four of his answers are correct, but the only change is that 5 is c. I got a 5/5 on this with his first 4 answers and then Austin saying it was C. Which is correct.

History
Really far north it would be september?

History
What time of year does snow come to the far north?

Math
I'm less than a hundred, the sum of my digits 17, I am a even number

Art

I'm just a girl that has no friends is correct. Just got a 100

chemistry Drbobz222
How do i convert mols CaCl2 to AgCl

biology
What role does the lilac flower play in its natural ecosystem? What is its niche in the food web Are there any ecological issues surrounding the lilac flower(e.g. are its populations decreasing, is it spreading uncontrollably..)

Physics
is there a site that can also help me

Physics
my question is: What is the purpose of the resonator of a stringed instrument

Physics
What is the purpose of the resonator stringed instrument

History
July 4, 1776

chemistry
What is the final concentration of 35.7mL of 52.0% m/m solution that is diluted to 65.9ml? i am not sure how to caluclate this... but i know the formula is C1V1=C2V2

chemistry
What is the mass of 4.3 × 10 to the power of15 atoms of nickel (Ni)?

Chemistry
I don't understand.. under Sam

Chemistry
A sample of toluene, C7H8 has a mass of 74.5 g. How many moles of benzene does it contain? How many molecules does the sample contain? How many carbon atoms does it contain?

physics
The block of mass 1.43443 kg has an acceleration of 3.6 m/s^2 as shown. What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s^2 and the surface is frictionles

science
A 5.0 kg model vehicle travelling at 14 m/s experiences a rocket boost of 85 N ( in the direction of motion) for 20 s What is the resulting speed? The answer is 350 but i don't know how to get to that answer

Chemistry
Yo mama

Math
I don't get this eather i really would like to know how people get the answer

chemistry
Complete and balance the following reactions, where applicable. If no reaction occurs, write N.R. Li + H2O ---> KCI + F2 ---> Au + HNO3 ----> CI2 + NaF ---> Li + Fe(NO3)3 --->

chemistry
Why is it important to make sure that the volume of water and the starting temperature are the same in each trial ?

physics
A boy runs 18.4 blocks North, 12.9 blocks Northeast, and 19.7 blocks West. a)Determine the length of the displacement vector that goes from the starting point to his final position. b)Determine the direction of the displacement vector. Use counterclockwise as the positive ...

physics asap!!! thank you
A boy runs 18.4 blocks North, 12.9 blocks Northeast, and 19.7 blocks West. a)Determine the length of the displacement vector that goes from the starting point to his final position. b)Determine the direction of the displacement vector. Use counterclockwise as the positive ...

physics
The pilot of an aircraft wishes to fly due west in a 50.0 km/h wind blowing toward the south. The speed of the aircraft in the absence of a wind is 228 km/h. a) How many degrees from west should the aircraft head? Let clockwise be positive. Answer in units of degrees. b) What ...

Math
Figure it out its hw so stop searching it up

Chemistry
A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength at this speed if his mass is 84.5 kg?

physics
Cameron kicks a football with an initial vertical velocity of 18.5 m/s and an initial horizontal velocity of 18 m/s and there is a flight time of approximately 2.0 s. Will the field goal travel far enough to make the field goal from 29 m away (if the ball is high enough to ...

Physics
How long is Mayra, a ballerina, in the air when she leaps straight up with a speed of 1.23 m/s?

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