2nd law Definition and 292 Threads

According to the 2nd law of thermodynamics, a spontaneous process will occur (or rather: is very likely to occur) if \Delta S > 0. A chemical process occurs if \Delta G < 0, where G = H - TS. Example: H = -100 kJ T = 1 K S = -10 kJ/K so \Delta G = - 190 kJ. In this example, \Delta...

How much are we justified in applying Newton's 2nd law in predicting trajectories of a single charged particle?What will be the answer for a number of charges?Of course, we have cyclotron motion at hand, but still...as we know, sub atomic level physics needs quantum mechanical consideration and...

How do car bumpers that collapse on impact help to protect a driver? According to the law of conservation of momentum, p = mv. Newton's 2nd Law is F = ma, or F = mv/t. So as t increases, F would decrease, thus less force would be acting on the car at a given time interval. Any...

Can you please help me out with this problem?!? Suppose that a 1000 kg car is traveling at 25 m/s (about 55 mph). It brakes can apply a force of 5000 N. What is the minimum distance required for the car to stop. :confused:

A block is propelled up a 48 degree frictionless inclined plane with an initial velocity of 1.20 m/s...A) how far up the plane does the block go before coming to a rest. B) How long does it take to move to that position? for part A) , i have initial velocity and I am looking for x...

Problem : A car is to tow a 2,270kg truck with a rope. How strong should the rope be so that it will not break when accelerating the truck from rest to 3.00 m/s in 12.0 seconds? So I assume it wants me to find the tension?...but the 12 seconds is throwing me off...I'm not sure what that...

I know Kirchoff's 2nd law but when applying to an electrical circuit i am bit confused :confused: with taking correct signs for emf,product of resistor & currect etc. Anyone please help me to solve problems related with Kirchoff's 2nd law in an easy way.

Newton's 2nd law with an incline plane (I think...help0 The 1930 kg cable car shown in the figure descends a 200-m-high hill. In addition to its brakes, the cable car controls its speed by pulling an 1830 kg counterweight up the other side of the hill. The rolling friction of both the cable car...

I really need help with this question. I've tried solving it but i just can't do it. The question A loaded dump-truck having a total mass of 2.4*10power of 4 kg is traveling east at 85km/h.The truck driver can apply a braking force of 5.5*10 power of 4 to the wheels without causing the...

I came across some questions where one box's magnitude of acceleration differed from another box's magnitude of acceleration. Please explain why and how this can be true. Thank you.

(Please look at the diagram attached at the bottom) Question: Newton's 2nd law, F=ma, is a vector equation. To add or subtract vectors it is often easiest to decompose the vector into components. Whereas a particular set of vector components is only valid in a particular coordinate...

Need Help with "Applying Newton's 2nd Law" What is \sum F_{2x}, the sum of the x components of the forces acting on block 2? Take forces acting up the incline to be positive. Express your answer in terms of some or all of the variables tension T, m_2, the magnitude of the acceleration of...

I have read in wikipedia and other places that white holes cannot exist as they violate the second law of thermodynamics. I s'pose my question is a simple one. How?

hello everyone, Im new to this forum but i really need some help doing a physics assignment. I am trying to use Newtons second law and the equation for wind resistance(click link) to determine the the angle made by a specific velocity. The link to the assignment is...

Here's the problem: An object is hung from a spring balance attached to the ceiling of an elevator cab. The balance reads 66 N when the cab is standing still. What is the reading when the cab is moving upward (a) with a constant speed of 7.6 m/s and (b) with a speed of 7.6 m/s while...

Alright, here's the problem: A block is projected up a frictionless inclined plane with initial speed v0 = 7.917811929967 m/s. The angle of incline is = 36.8°. (a) How far up the plane does it go? (b) How long does it take to get there? (c) What is its speed when it gets back to the bottom...

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The position of a particle of mass m moving in a circular orbit with radius r = ro is given by: r(t) = ro <er> Show using Newton's second law of motion, that if the force responsible for this motion is given by: F = -k/r^2 <er> a) the angular velocity is constant in time, and b) the...

This is hard to explain without having a picture, but there is a 1 kg hanging off the table. And a string is connected from that to a 10kg weight. From that weight on the other side, a 5kg weight hangs off the table. They system is moving to the left at 2 m/s. Do I have to compensate for that...

I was wondering if it was possible, via biological thermodynamics, to demonstrate that evolution does not violate the 2nd law of thermodynamics in mathematical terms. From my understanding, the Earth is a closed system (this seemed odd, but I read this in a book on biological thermodynamics. I...

people who believe in creation say evolution violates the 2nd law of thermodynamics. those who believe in evolution say it does not. who's right? if it does violate the 2nd law of thermodynamics why and how? i just want to know who's right on this issue. p.s. sorry if this has been asked before...

I along with a buddy of mine in the same course have been trying to figure out the following question. We spent at least an hour and a half to two hours and nothing makes sense. Any help would be greatly appreciated. Here's the question as it's written: One way to measure the acceleration...

Here's the problem...unfortunately I don't remember much about orbital motion. I'm a bit stuck on where to begin. If somebody could give me a little advice on how to tackle this problem I would appreciate it. Recall that the magnetic force on a charge q moving with velocity v in a magnetic...

Hello! I was given two formulae for my Physics lab: ma=mg-T and T=Ma (using a pulley). ma--> net force on small object (paper clip) M--> larger mass (glider) mg--> force of gravity a--> acceleration T--> tension of ribbon used I'm...

I figured out the horizontal friction force, Fpx to be 55.11 N and the normal force exerted vertically to be 190.8 N. And the other info given is F = 84 the lawn mower has a mass of 13 kg and moves at a constant speed. The lawn mower is at an angle of 49 degrees to the horizontal. I need to...

Why is the definition different in physics and chemistry for the 2nd law of thermodynamics?

if a guy is in an elevator (55 kg for the person), and then he jumps straight uo- the scale will read 622 N. what is the acceleration of the guy at this instant? how do you deal with this b/c i don't know how to do it unless he is still standing on the scale. i know there should be an...

Hello! I have a few homework problems that I'm just not sure what to do with: 1) A soccer ball rolls down a hill, reaching the bottom with a speed of 10.0 m/s. The coefficient of friction between the ball and the grass on the hill is .80. How far does the ball travel on the surface before...

If i am given information involving a particle and I know the resulting velocity (in x and y direction) and one of the beginning forces in Newtons (x and y components as well), how do i figure out the other beginning force? I'm given no information about angles or the mass of the object

Q. In the Bohr model of the hydrogen atom, the speed of the electron is approximately 2.20 x 10^6 m/s. Find (a) the force acting on the electron as it revolves in a circular orbit of radius 0.530 x 10^-10 m and (b) the centripetal acceleration of the electron. I'm going to...

A 10 kg mass experiences twice the gravitational force as a 5 kg mass. Why doesn't the 10 kg mass fall faster than the 5 kg mass? I never understood the reason. All I know is that Galileo found that objects dropped near the Earth's surface will fall faster with the same acceleration or g...

Did Newton accidentally reverse the order of his laws of motion? The 1st law implicitly established the notion of time and conservation of energy. The 3rd law formulated the conservation of linear momentum by m_1v_1 + m_2v_2 = constant the time derivative of this expression is m_1a_1...

Hello List, I understand Boltzmann defined entropy [S] as log W where W is the number of microstates in the system time a constant "k" ; hence S= k Log W. Can someone explain to me where the logarithmic relationship comes from please ? Many thanks in advance, Celal Berker London...

Hey everyone~ A 2.0 kg toy locomotive is pulling a 1.0 kg caboose. The frictional force of the track on the caboose is 0.50 N backward along the track. Of the train is accelerating foward at 3.0 m/s^2, what is the magnitude of the force exerted by the locomotive on the caboose? So I'm...

MIT Professor vs. all college books Hi there! I'm a first year student and found quite interesting the MIT on-line video lectures on electromagnetism. http://ocw.mit.edu/OcwWeb/Physics/8-02Electricity-and-MagnetismSpring2002/VideoLectures/index.htm In one these lectures given by Dr...

Is force the cause of motion? If there is motion would there be a force also? Newton's 1st law of motion says there can be motion even without force. This motion is a constant velocity (in particular such as the constant speed of light in vacuum). Newton's 2nd law of motion says that the...

Hi, I was just wondering what the actual proof is for the second law of thermodynamics that would disprove a situation where all particles are simply reversed in direction creating lower entropy? Is it a consequence of another scientific principle or where does it come from? sincerely, jeffceth

here's the question: A uniform rod of length 1.15 m is attached to a frictionless pivot at one end. It is released from rest from an angle of 27 degrees above the horizontal. Find the magnitude of the initial acceleration of the rod's center of mass. So far I've only been able to figure...

in this link someone claims an increase in order that is against the 2nd law http://news.bbc.co.uk/1/hi/sci/tech/2135779.stm is a 1/10 sec time frame valid or just random chance anyone got a better link to this I found this pdf http://rsc.anu.edu.au/~evans/papers/exptFT.pdf on...

I have read two contraditory explanations of why the 2nd Law of Thermodynamics would prohibit an oscillating universe ad infinitum. The first one, from a Paul Davies Books states that the second law of thermodynamics only would permit the oscillations to become larger each time. While this...

d2A/dt2=0 or dA/dt=k=rv/2 L=r x p L/m=r x v L/(2m)=(r x v)/2 How does dA/dt relate to L? In a certain book, it says dA/dt=H/2 where H=L/m=rv but L is a vector and H is not.

hi, I am new and I am dumb, so this is probably a really obviously answered question, but: everyone knows the second law of thermodynamics, right? that is, entropy in a closed system can only be increased. if you take the universe as a closed system (a little like the ultimate closed system...