Third law Definition and 377 Threads

Are there any examples of violation of Newton's third law? The two examples that I know are : 1) Two masses moving relativistically apart from each other. 2) Two charges moving in mutulally perpendicular directions. Can anybody further elaborate on these exmaples with proper explanation and...

I hate all of Newton's laws questions. They are so complicated. Can anyone please help me with this question. A boy pushes a lawn mower (m=17.9 kg) starts from rest across a horizontal lawn by applying a force of 32.9 N straight along the handle, which is inclined at an angle of 35.1 degrees...

Question: Mass m1 on the frictionless table is connected by a string through a hole in the table to a hanging mass m2. With what speed must m1 rotate in a circle of radius r if m2 is to remain hanging at rest? My answer: Fnetym2 = T - m2g For m2, a = 0 Therefore, 0 = T - m2g T = m2g...

not sure what to do here.. Im being asked to compare the periods of 2 different satellites in orbit around a planet. the first one is a circular orbit of radius = r the second one orbits 1r to the left and 3r to the right around the planet. I'll attempt to draw it here :-p 0...

Three toboggans are attached to each other with ropes. A force of 145 N[forward] is pulling the first toboggan, which has a mass of 42kg. A second toboggan, with a mass of 30kg, is attached to the first second toboggan. A third toboggan with a mass of 24kg, is attached to the second toboggan...

Pushy Astronaut -------------------------------------------------------------------------------- a) An astronaut of mass 70 kg pushes off a satellite of mass 420 kg, exerting a force of 120 N for the 0.83 s they are in contact. What is the speed of the astronaut after they have separated...

So I have a homework question that says: A 100 kg hockey player a 112kg hockey player collide with each other each traveling with a force of 50N. The textbook answer says that the acceleration of the 112kg is 0.89m/s^2 and the acceleration of the 100kg player is -1.0 m/s^2. I'm confused...

The inverse square law for gravitation was deduced from Kepler's third law. So how was the inverse square law for electrostatics(Coulomb's law) deduced?

Hello, I wonder if any of you would be kind enough to help a layman? I seem to remember a friend once told me that everything vibrates, and that nothing would exist if it didn't vibrate. For starters is this correct, or have I remembered incorrectly? Also, what is he talking about? Someone has...

One question related to Newton's third law, v t p u o u o It is a rope with a wheel,v. If 50N is applied from u pulling towards the ground, what's...

Yesterday, one of my cousins asked me about Newton's third law. In this discussion he asked me this question: Why does not a bullet bounce back after striking the surface of glass as it does in the case of steel, considering that in both the cases the force with which it strikes the glass or...

Why we move foward: The applied force from our foot pushs on the Earth and therefore, according to Newton's 3rd law, the Earth pushes back on me to make me move foward. Yeah, this is like basic material, but just need a verification, is this correct?

Newton's third law states something along the lines of "For every action, there is an equal and opposite reaction." The problem I have is that I don't understand how it stays true for something as simple as pushing a box. If a push the box (action), how can it be giving an equal opposite...

If there was a block on a table what would be the normal force between the block and the table. If you could describe the free body diagram that would be great too.

When object A and object B collide, where A is moving and B is stationary and where B seems to compress: Does B expand in response because a pre-existing internal force exists in B and exerts an equal and opposite reaction, or Is the entity motion transferred from A to B redirected back...

PLEASE help! Kepler's third law for electrical orbits Hi there! I hope someone can help me with this problem. I've been working on this for over 5 hours and I've gotten nowhere! :eek: A positron is a particle with the same mass as an electron but with a positive charge. A positron and an...

I can not find the answer for this In a rotating frame of reference, Newton's first and second laws remain valid if we assume that a fictitious force equal to mv^2/r is acting. What effect does this assumption have on the validity of Newton's 3rd law?

hi, Before i begin i am not sure where to put this post wether here or in the general section. Is Newtons 3rd law broken? Neutrinos don't follow this rule. the neutrinos can just pass through particles. so don't they break the 3rd rule? :confused:

Although the equal and opposite forces stated in Newton's third law are sometimes referred to as an action-reaction pair in reality they do not share a cause and effect relationship. They arise simultaneously, abide together and disappear simultaneously. Imagine you are spinning a washer...

hi...my teacher has offered an optional project of creating something that used Newton's third law.. I've been trying to think of something but i don't have any ideas... i have to make something .. and umm it can't be a fan on wheel blowing against a wall because that's the example in the book...

can someone explain to me Newton's thrid law of motion?

I'm not good at this stuff, so I need some help from some smarter people...:smile: The speed of the Sun in its orbit about the Galactic center is 220 km/sec. Its distance from the center is 8500 pc. Assuming that the Sun's orbit is circular, calculate the mass of the Galaxy (in solar...

How did Kepler come about to conclude that his third law is Radius3/Period2? How did he derive this equation?

Hi, I just got my physics test back and am hoping I can be helped with two questions. My instructor gave it back at the end of class leaving no time for going over it. 1) Suppose the period of the moon in its orbit about the Earth were 41.1 days and the moon were 768,000 km from earth...

I was engaged in a discussion where someone claimed that Newton's Third Law does not apply to the lift created by air flow over a wing. My argument goes as follows: After all the equations, etc. involving fluid dynamics and Bernoulli's principle there is an upward force on the wing...

Hello! I've just begun attempting to teach myself physics, and I'm finding it difficult to understand Newton's third law. Would someone be so kind as to shed a little light on the situation? The idea of the equal and opposite reaction for every action makes perfect sense to me in some...

I have attached a drawing that depicts the situation of two electromagetic coils in space separated by a vast distance. It seems to me that in this case there would be a magnetic action force on the right coil but no reaction on the left coil. I'm probably missing something here but I would...