A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

# Questions tagged [newtonian-mechanics]

Newtonian mechanics covers the discussion of the movement of classical bodies under the influence of forces by making use of Newton’s three laws. For more general discussion of energy, momentum conservation etc., use classical-mechanics, for Newton’s description of gravity, use newtonian-gravity.

12,342 questions
Filter by
Sorted by
Tagged with
2k views

### Path to obtain the shortest traveling time

Asume we have a particle sitting at the point A(0,0) in a gravitational field. (g=9.81) It is going to move along some path to the point B(a,b) Where a>0 and b<0. What is the curve the particle ...
4k views

### Why does this object periodically turn itself?

See below gif image taken from here. Or see this Youtube video about 30 sec in. Is this a real effect? Why does it seem to turn periodically? Can it be explained by classical mechanics alone? Is ...
18k views

### Is there any true inertial reference frame in the universe?

Is there any true inertial reference frame in the universe? Newton's first law states that an object at rest remains at rest, and an object performing uniform motion performs uniform motion, until ...
12k views

### Vertical component of moving weight at a 45 degree angle

Here's an easier one. I use the leg press machine at the gym so I don't have to worrying about hurting myself while lifting heavier weight. The weight glides on a track that looks to be 45 degrees. ...
1k views

### Why does the Earth rotate? [duplicate]

Possible Duplicate: Why does every thing spin? So why would the Earth, or any planet for that matter, rotate along an axis? I know of no force which could come into play here, so i assume it just ...
350 views

### Projectile motion equations @ very (!) high starting velocity [duplicate]

I've already searched Physics StackExchange for some similar question but I didn't find anything about this. Assumptions: Earth is a perfect sphere with it's core (X,Y,Z) -> (0,0,0) as a reference-...
7k views

### How does a mobile phone vibrate without any external force?

How does a mobile phone vibrate without any external force? By Newton's law, any body can't move without any external force
4k views

### Escape velocity of a rocket standing on Ganymede (Moon of Jupiter) [closed]

I want to calculate the escape velocity of a rocket, standing on the surface of Ganymede (moon of Jupiter) and trying to leave Ganymede. My thinking was, the kinetic energy $E_{\text{KIN}}$ must be ...
2k views

### How do I express the Kepler general orbit $r(\phi)$ in rectangular coordinates?

How do I express the Kepler general orbit $r(\phi)$ in rectangular coordinates? I use the identities $x=r\cos\phi$, $y=r\sin\phi$, and $r^2 = x^2 + y^2$, but I block at some point.
2k views

### Why do some satellites fall to Earth?

In another question How does Newtonian mechanics explain why orbiting objects do not fall to the object they are orbiting?, one can read an affirmative answer. They how do you explain satellites ...
91k views

### How does force affect velocity?

I know that a force will change the magnitude of velocity if it is at an angle other that 90 degrees. If the force is perpendicular to the velocity it will cause the path of the object to curve and ...
3k views

### Inertial frames of reference

I'm struggling with the notion of an inertial frame of reference. I suspect my difficulty lies with the difference between Newtonian and relativistic inertial frames, but I can't see it. I've read ...
166 views

### Question regarding escape velocity

Haliday-Resnick-Walker state that the escape velocity will cause a projectile to move upward forever, theoretically coming to rest only at infinity. I was wondering what the forces forcing the body ...
6k views

### Is there an intuitive reason the brachistochrone and the tautochrone are the same curve?

The brachistochrone problem asks what shape a hill should be so a ball slides down in the least time. The tautochrone problem asks what shape yields an oscillation frequency that is independent of ...
3k views

### Why are there both Static and Kinetic Friction?

When dragging an object, there is a greater start-up force than the force it takes to keep it moving. Why is this? Why are there two different values for friction?
222 views

### Movement of a nudged block on a high friction surface

If I apply a single force to an object ‘floating in free space’, then it will either translate (if the force is in line with the Cof G ) or more generally it‘ll rotate about the C of G due to the ...
133 views

### Would a projectile keep going forever in empty space?

Would a projectile fired in space and assuming there were no stars or planets in the way, would the projectile continue on to infinity, since the x-component of the projectile's velocity never changes ...
4k views

### Classical car collision [duplicate]

I have a very confusing discussion with a friend of mine. 2 cars ($car_a$ and $car_b$) of the same mass $m$ are on a collision course. Both cars travel at $50_\frac{km}{h}$ towards each other. They ...
327 views

### Impulse situation

I am wondering if a physical system subjected to an impulse $=A\delta(x-a)$ makes any sense. I reckon that a force could take that form -- thought of as a finite impulse applied over an infinitesimal ...
82 views

### On the topic of action and reaction

So, let's say we have a spacecraft in deep space. It activates its rocket engines, to keep it simple. The engine reaction channels exhaust through the aft nozzle, right? How does that chemical ...
13k views

### Net work done on the body when we lift it and put it on the table is zero?

I'm little confused here. Work done on the body when we lift it and put it on the table is zero, because according to work energy theorem, change in kinetic energy of the body is zero. So, the net ...
2k views

### Arnold´s Math Methods of Classical Mechs - a question on Newtonian Mechanics

There is the following question/answer on Arnold´s book Mathematical Methods of Classical page 10. Arnold's Question A mechanical system consists of two points. At the initial moment their ...
15k views

### Dependence of Friction on Area

Is friction really independent of area? The friction force, $f_s = \mu_s N$. The equation says that friction only depends on the normal force, which is $N = W = mg$, and nature of sliding surface, ...
3k views

### Use the relative velocity formula to find $v_{2f}$ in terms of $v_{1f}$?

Q: A $0.150\text{ kg}$ glider is moving to the right ($+x$) on a frictionless, horizontal air track with a speed of $0.80\text{ m/s}$. It has an elastic collision with a $0.300\text{ kg}$ glider ...
6k views

### Does conservation of momentum really imply Newton's third law?

I often heard that conservation of momentum is nothing else than Newton's third law. Ok, If you have only two interacting particles in the universe, this seems to be quite obvious. However if you ...
75 views

### How do I find the frictional force using a free body diagram? [duplicate]

Possible Duplicate: Free Body Diagram I have this problem: A person push a 16 kg lawn mower at constant speed with a force of 80 Newtons directed along the handle which is at an angle of 45 ...
1k views

### What is a Free Body Diagram?

I have this problem: A 10 kg box is resting on a frictionless table and someone drags it by a string at a 30 degree angle to the horizontal with a force of 40 Newtons. Find the acceleration of the ...
7k views

### Bullet trajectory at different angles

I've read from different sources (can't find them online) that firing a bullet at different angles from horizontal will result in differing amount of bullet drop. For example, a gun is fired at a ...
525 views

### Vertical Motion in Air + Density [closed]

I am having trouble with this confusing question. Please help. The fastest recorded skydive was by an Air Force officer who jumped from a helium balloon at an elevation of 103000 ft, three times ...
773 views

### Realistic projectile motion

I am working on a project involving a simulation of the motion of a projectile (in 3D) aimed at a moving target. The way projectile motion is analyzed in most introductory physics books is not ...
676 views

### Kinetic energy puzzle

System S1 moves at constant speed V with respect to S0 in one dimension: ...