newtons 3rd law Definition and 19 Threads

if a box is sitting on a flat surface and I apply 10 N on it, then the box would apply 10 N on my hands, but the static friction (assuming maximum static friction is greater than 10 N), would oppose the applied force with 10 N thereby keeping the box at rest. what I do not understand is this: is...

I would say that it will not break in both cases, since tension force is 10 N, no matter if I pull it against a tree or a person. But I am not sure. How is it?

This is the initial setup of the problem: The electric field due to the ring is: $$E = \int\frac{k(dq)}{(\sqrt{R^2 + x^2})^2}\frac{x}{\sqrt{R^2 + x^2}} = \frac{kqx}{(R^2 + x^2)^{3/2}}$$ the force on the rod due to this Electric field produced by the ring is: Consider a differential element...

Hi, I have a conceptual question. I was doing some problems on pendulums and found something that confused me. I attached a drawing. I used to always solve these problems by using some trigonometry and trying to find the Tension. i.e. ## m*g = F (of the Tension) * cos(theta) ## so ## \frac...

I couldn't remember which number was which in Newton's laws of motion, and so I clicked the first link I found, but to my amazement it seems that while Rice University got the number right, they got the facts of how it works wrong. Ironically it seems they have made the same mistake as that...

In relation to two objects with a gravitational field on them (i.e. a planet and its moon), would there be two pairs of partner forces (the force of gravity exerted from each object and the resulting partner force from each force of gravity)? For example with the Earth and moon: 1. Force of...

Hi I'm having trouble understanding this situation. Appologies if I posted in the wrong place, this is pretty simple but it's not really a homework question. A horse is attached to a large stone by means of a rope (modelled as light and inextensible). Let the mass of the horse be m and the...

I having a little trouble grasping the 3rd law because of this idea in my head about a situation where a large truck going very very fast hits a person standing still. 1)Lets say the truck is going fast enough where the person's body will slightly rupture due to the impact. How can that tiny...

Homework Statement A 2.5 kg mass is attached to a 3.5 kg mass by a light string that passes over a friction-less pulley. The masses are released. a) What is the magnitude of the acceleration of the masses? b) What is the tension in the string? Homework Equations (I think) Ft - mg = ma The...

I would like to know how much of a % does Newtons 3rd law (action / reaction) account for lift of a chopper.. i would also like to know this for Bernoulli's principle.. Can you give a source to back it up? I can't find an answer any where

If I were to take a standard sharp led pencil and push it on my desk, the tip of pencil will feel the same force as the force exerted on the desk, but what about the pressure? Since pressure is defined as: P = F / A The surface area of the tip of the sharp pencil is far smaller than...

how do you find the Tension force,acceleration,magnitude. Its those questions where you have pullys,boxes pushing each other... I am really confused for the 3rd law

Homework Statement The coefficient of static friction is 0.60 between the two blocks in figure. The coefficient of kinetic friction between the lower block and the floor is 0.20. Force causes both blocks to cross a distance of 5.0 m, starting from rest. What is the least amount of time in...

I understand the law and can apply it to many situations except for one. You are pulling a box weighing X kg attached by a connection which isn't loose or anything to another box weighing Y kg and you have to find out the strength of the opposing forces inbetween the boxes. Why is there...

Homework Statement show that the forces between two current loops obey Newtons 3rd law. Homework Equations \textbf{F}_{12}=\frac{\mu I_{1}I_{2}}{4 \pi s^{2}} d\textbf{r}_{1}\times(d\textbf{r}_{2}\times \textbf{s}) s is the distance between the elements of current The Attempt at a Solution...

I have to apply the 3rd law i think to this, just not sure how to. A 2000 kg motorboat's propeller pushes on the water toward the west with a 2000 N force. The wind blowing toward the south pushes the motorboat with a 500 N force. Determine the location of the motorboat 10 seconds from the...

I am needing help on a few problems that I have to do for class. If anyone could help on any of them that would be great. 1)Bob, who has a mass of 75 kg, can throw a 500 g rock with a speed of 30 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until...

Hi I need help on these questions, please try to be specific. A sled dog pulls 2 sleds, A and B mu=0.10 If tension in rope 1 is 150 N What is the tension in rope 2? ----------------------------------- Mass 1 on a table (mu=0) is connected by string through a hole in the table to a...