Recent content by ortegavs

Homework Statement Homework Equations T=2pi(sq.root L/g) The Attempt at a Solutioncombined a=1/2 V^2/r with a=g(sinO) then solved for v. got v=Sq.root 2gL(sinO). Don't know if this is right.

I think I understand. The answer that I provided is for the equation which has 2 mols of water. The correct answer is kJ/mol not per 2mols so I have to divide by 2 to get the correct answer. Can someone back me up on this?

Homework Statement What is the standard Gibbs free energy of formation of water vapor at 25 C, if , for the reaction shown below under standard conditions, Δ H = -484 KJ/mol and ΔS= -89 J/mol K? 2H2(g) + O2(g) >>> 2H2O(g) Homework Equations ΔG = ΔH - TΔS The Attempt at a...

Ok I think I got it. Since the object is moving in a circle then it is constantly changing its direction thus its acceleration is not constant as I had assumed. Given this I cannot use kinematic equation V avg = Vf+Vi/2 since this equation requires constant a. Thus I have to us the other...

Jay Points A and B do lie on a horiz. axis. The definition of average V is vi +vf/2. I don't understand why I can't use this definition? And if you use to points A and B you have to divide by two I don't understand. So with the your definition V avg= xf-xi/t which is 5/1/2 and this equal to...

Homework Statement A particle moving from position 1 to position 2 moves along path C ( which is half a circle ). It travels at a constant speed of 5 pi m/s. At exactly half way ( 1/4 of a circle ) through the trip its average vertical velocity is? Radius is 5 meters. Homework Equations...

So there is no way of knowing with the information given if the starting frequency is 438 or 442? I thought about that also and reason that the final f should be found with the information given but the starting frequency, I just couldn't make a connection with anything.

Homework Statement Ok so a piano tuner plays an out of tune A note on his piano and then strikes his 440 hz tuning fork. He notices a beat of 2 Hz. When he loosens the piano string and plays the note again, the beat goes to 4 hz. What was the frequency of the note before he loosened the...

You can also use unit analysis (rev/2πr)(10m/s) which gives 20 rev/π s. Its so frustrating that I spend 30 minutes on such a simple problem. The other solution posted also checks, thanks.

Homework Statement If the radius of the wheel on a bike is .25m, and has a velocity of 10m/s, how many revolutions does the wheel make each second?Homework Equations 2πr/rev The Attempt at a SolutionI solved this problem in terms of pi. First each rev moves the wheel 2πr which is 2π(1/4)=1/2π...

Homework Statement Which of the following could be accomplished with the least average force? a: accelerating a 2 kg ball from 0 m/s to 9 m/s in half a second. b: accelerating a 6 kg ball from 0 m/s to 6 m/s in one second. c: accelerating a 9 kg ball from 0 m/s to 8 m/s in two seconds. d...

Homework Statement A bucket full of water is slid across a sheet of ice in the rain. As the bucket fills, what happens to its velocity and its momentum? ( assume no friction) Homework Equations P=mv The Attempt at a SolutionI reasoned that since the bucket gained mass it gained...

Homework Statement Ok so a 25kg mass is lowered by a rope. If the velocity of the mass is decreasing at a rate of 5m/s(squared), what is the tension in the rope? Homework Equations T-mg=ma T-mg= -ma The Attempt at a Solution I solved for the 1st equation to get the answer of 375N...