Second law Definition and 491 Threads

Hi, I have a question on Newton's second law. I have a box in which an egg rests inside. Egg is surrounded by some sort of padding. A force is applied to the box. (Force has an x and -y component. Are my conclutions right? 1) Force act on the box, not on the egg. Applying Newton's...

I've thinked an experiment. We have two containers that contain two liquids. One container contains a liquid that have small molecules and with high specific weight. The second container contains a liquid that have molecules greater and low specific weight. Now we connect the two container...

Newton's second law! According to Newton's second law if the resultant force acting on a body is non zero the body moves with an acceleration proportional to the mass of the body, right?Then, 1. Can anyone explain this in an intuitive sense? 2. In solving problems we say that the resultant...

I'm reading through an example involving Newton's second law. The situation is that there are n particles surrounded by a system boundary. The picture consists of a bunch of circles (particles) enclosed by a closed loop. The forces acting on one of the particles of mass m_i consist of an...

Question answered! Thanks for the input!

I was wondering if anyone had some input on how, via calculus, to show how the law of conservation of mechanical energy for an object in free fall (ideal) is a direct consequence of the of Newtons second law.

Could anybody of you verify my answers here please... it's really important for me to know if I'm doing it right! A mass m2= 10 kg slides on a frictionless table. The coefficients of static and kinetic friction between m2 and m1 = 5 kg are us= 0.6 and uk= 0.4...

Can anyone please help me with these two problems?? I have been trying to figure them out for a while, but cant... 1. A net force of 125 N acts on an object. Find the single force that will produce equlibrium? Is the answer a force of -125N acting back on the object?? Seems...

I have absolutely no idea how to do this problem and I need help with steps, formulas/equations, etc. So, here it goes! David Purley, a racing driver, survived deceleration from 173 km/h to 0 km/h over a distance of 0.660 m when his car crashed. Assume that Purley's mass is 70 kg. What is the...

Only two horizontal forces act on a 3.0 kg body. One force is 9.0N, acting due east, and the othr is 8N, acting 62 degrees north of west. What is the magnitude of the body's acceleration? Fnet= ma ...so I took that to mean F1x + F2x = ma F1x = 9 cos 0 = 9 f2x = 8 cos 62 = 3.76 a = (9 +...

Is someone able to proove the invariance under Galilean transformations of F=dp/dt within a system of variable mass? In particular is the momentum invariant? i.e. p=p', as Goldstein states? Please answer me! :wink:

Three astronauts, propelled by jetpacks, push a 120kg asteroid toward a processing dock, exerting the forces F1 = 32N at 30 degrees above the horizontal F2 = 55N on the horizontal F3 = 41N below 60 degrees below the horizontal what is the asteroids acceleration in unit vector notation...

Hi, I'm a little confused with this problem: Ok, basically what I did so far is to draw the vectors from the origin of both the velocity and the first force. For the velocity, I made a vector(?) with a slope of (-4/3) and a magnitude of 5. For the first force, I made a vector(?) with a slope...

An advertisement claims that a particular automobile can "stop on a dime." What net force would actually be necessary to stop an automobile of mass (m) traveling initially at a speed of (v) in a distance equal to the diameter of a dime, which is (d) ?

This question is driving me insane... An arrow, starting from rest, leaves the bow with a speed of 25.0 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the arrow leave the bow? Of course, instinct says 50 m/s, but...

I'm not sure if this is the right place for this thread, so I'm sorry if it isn't; well, I have a question about Entropy and the second law of thermodynamics, if supposedly we can't remember the future because our brain has to use up energy to create memories and thus increases the entropy and...

Hi I got a few questions that I could not answer about Newton's Second Law of Motion. Can someone please help me? 1) A 1.08 x 10^3 kg car uniformly accelerates for 12.0s from rest.. During this time the car travels 132 m north. What is the net force acting on the car during this acceleration...

Consider another special case in which the inclined plane is vertical (\theta=\pi/2). In this case, for what value of m_1 would the acceleration of the two blocks be equal to zero? Express your answer in terms of some or all of the variables m_2 and g. a good point in the direction will help

The logic conflict of the second law of thermodynamics The description of the second law of thermodynamics is that the thermal activity of an independent system always make entropy increase and make it maximum(stable balance) There is some requirement for the subject of the second law of...

Is the maximum efficiency possible in an energy conversion process that is not limited by the Second Law 100%?

question is http://home.earthlink.net/~urban-xrisis/clip_image002.jpg I know that an imaginary line adjoining a planet and a sun sweeps out an equal area of space in equal amounts of time. that means... I know that \frac{1}{2}b(t_2-t_1)=\frac{1}{2}b(t_4-3_1) but I don't know that...

Hi all, Can the second law of Thermodynamics be proven? (I mean, starting with the definition S=kln(Ohmega).) If not.. is it just an empiric fact?

What mathematical relationship exists between acceleration and unbalanced force (direct, inverse) What mathematical relationship exists between acceleration and mass Just need help solidying my answers, any help will be appreciated

Hi. I have this problem: The fastest cars can travel at 350km/h. When you take the foot of the gaspedal the air will decrease the speed of the car. This leads to a retardation (I hope it's the right word for it) at 1.1 g. Which force (N) will affect the driver (80kg)? The weight of the car...

A locomotive steam engine opperating with a total train mass of 99.9x10^6 kg climbs a hill of height 1000m in 10 minutes. If the steam engine produces steam at a temperature of 390k and exhausts steam at 300k, and if the engine were at the theoretically best efficiency possible, what would be...

An ideal gas is confined within a thermally isolated cylinder. It consists of N atoms initially at a pressure of p_0. A movable piston seals the right end of the cylinder. A given amount of heat Q is slowly added to the gas, while the piston allows the gas to expand in such a way that the gas's...

First Formulation of Second Law as "F=ma"? Newton expressed his Second Law of Motion as .Who was the first to put it into the modern form F=ma? Was it Descartes?

A block of mass 2.0kg is placed on a smooth plane, inclined to the horizontal at an angle of 15degrees. The force of gravity, acting straight down on the block, is 20N. a) What is the acceleration of the block down the plane? I'm having trouble with this because I know: Net...

I'm new to thermodynamics and was looking at the second law. From what I know, the 2nd law is constantly violated locally (in a non-isolated system), but this violation locally causes an increase in entropy in an isolated system. Am I right here? or is my understanding flawed? if its not, then...

Science howework A crate rests on a horiontal floor. Only gravity and the support force of the floor act on it. A slight pull P is exerted on the crate, not enough to move it. A force of friction f now acts on it. is f, less than, equal, or greater than P? is the net force on the crate...

Background: suppose that we have single body say sphere and nothing else in the universe. Now it will radiate heat depending on its temperature.since its energy is going down its temperature will decrease.Eventually wel have energy in the form of photons and sphere at zero kelvin. thus In...

The differential equations that are mostly used in physics are second order, so I am wondering about the third order (or more)? It is clear that in real life, like when driving a car, acceleration changes many times and continuously, but do people ever add d3x/dt3 to Newton's second law? Is it...

I was reading a section about rocket propulsion in my general physics text and it came up with the following formula: m \frac{dv}{dt} = - v_{ex} \frac{dm}{dt} I don't have much trouble with this formula, but then it went ahead and substituted m dv/dt as the thrust experianced by the...

I'm glad they passed this law because without it, your coffee spoons would never cool off.

While studying the history of classical mechanics I noticed that the primary motor for most of the early equations is the principle of conservation framed firstly as the law of inertia and then as the principle of least time (Fermat) and then as... But while trying to regain for the principle of...

A string wrapped around a cylinder, and is held by a hand (to the up right of the cylinder so the cylinder is rotating clockwise) that is accelerated upward so that the centre of mass of the cylinder does not move. a) Find the tension in the string. b) Find the angular acceleration of the...

To drag a 75kg log along the ground at constant velocity, you have to pull in it with a horizontal force of 250N. a) what is the resistive force exerted by the ground? b) what horizontal foce must you exert if you want to give the log an acceleration of 2m/s^2...

A 69 kg block is pushed along the celing with a constant applied force of 1300N that acts at an angle of 56 degrees with the horzontal. The block accelerates to the right at 8m/s^2. What is the magnitude of the normal force the ceiling exerts on the block? Answer in units of N. and A...

Hello everyone. I'm having a little trouble understanding the whole "ball and bowl" problem using Newton's Second Law. What I'm talking about involves a small shpere of mass m and radius r, rolling down a "bowl" (more like a hemisphere of radius R). How would one go about finding the KE of...

second law & universe Is the universe a closed thermodynamic system, as defined in the laws of thermodynamics? Some argue it is, or state it is, based on the fact that the universe is by definition everything there is, so it can't really be in thermal contact with anything else as itself...

This question has been troubling me... : A physics teacher decides to use bathroom scales (calibrated in Newtons) in an elevator. The scales provide a measure of the force with which they push up on the teacher. When the lift is stationary the reading on the bathroom scales is 823 N. What...