Tagged Questions
3
votes
2answers
72 views
Conservation of Linear Momentum at the point of collision
This is a pretty basic conceptual question about the conservation of linear momentum.
Consider an isolated system of 2 fixed-mass particles of masses $m_1$ and $m_2$ moving toward each other with ...
1
vote
4answers
198 views
Bat hitting a ball
When a bat hits a ball, consider two cases:
1) The batsman goes for a defense, and stonewalls it, to reduce its speed.
2) the batsman goes for a shot, e.g. a home-run, etc.
in which case will the ...
1
vote
1answer
83 views
Spring coupled platforms & conservation of momentum - can it be solved with freshman physics?
This question came up as an exercise in a first year undergraduate course I was a TA for. It turned out to be a lot more difficult (impossible?) than anticipated...
Two platforms of mass $M_1$ and ...
0
votes
1answer
101 views
Non-relativistic Kepler orbits
Consider the Newtonian gravitational potential at a distance of Sun:
$$\varphi \left ( r \right )~=~-\frac{GM}{r}.$$
I write the classical Lagrangian in spherical coordinates for a planet with mass ...
2
votes
3answers
202 views
Explanation for classic mechanics puzzle
I'm trying to figure out a nice way to describe to a kid the physics behind these experiments:
Assuming ideal conditions, we have a small boat with a sale, close to a lake's shore and a fan fixed on ...
3
votes
1answer
476 views
Conservation of linear and angular momentum
Suppose I have two rigid bodies A and B and they are connected by a spring which is attached off-center (thus possibly causing torques). Due to the spring a force $f$ acts on A and a force $-f$ acts ...
0
votes
2answers
155 views
Having Trouble With The Principle Of Conservation Of Momentum For a Multiparticle System
I'am reading John Taylor's Classical Mechanics chapter 1 page 20 where he proves the principle of conservation of momentum which states "If the net external force $F^{ext}$ on an $N$-particle system ...
0
votes
0answers
34 views
Does the direction of a rocket relative to an orbiting mass reduce the orbiting mass' orbital velocity?
Does a rocket taking off in the same direction of an orbiting mass (asteroid to planetary size) reduce the mass' orbital velocity versus the same rocket taking off in the opposite direction of the ...
4
votes
3answers
492 views
Why do we need the quantity momentum?
Why do we need the quantity Momentum in physics when we have the quantities like Force and Energy? Isn't it possible to substitute the usage of Momentum with equivalent of Force and Energy?
1
vote
1answer
162 views
How to determine n equidistant vectors from point P in three dimensions
As an assignment for uni I need to figure out an algorithm that explodes a particle of mass $m$, velocity $v$, into $n$ pieces.
For the first part of the assignment, the particle has mass $m$, ...
0
votes
2answers
88 views
The time for which rear moving block remain in contact with spring in the following situation? [closed]
I'm a physics tutor. I'm stuck up with this question. I've no clue about how to proceed with this question. Can any one help?
A 2 Kg block moving with 10 m/s strikes a spring of constant π^2 N/m ...
1
vote
1answer
591 views
Converting angular velocity to linear velocity through friction
A very basic question here; it's related to this one, but not quite the same.
If a rotating rigid body (a sphere for the sake of discussion) with mass $m$, radius $r$ and inertial tensor $I$ has ...
4
votes
4answers
225 views
Applications of recoil principle in classical physics
Are there any interesting, important or (for the non physicist) astonishing examples where the recoil principle (as special case of conservation of linear momentum) is applied beside rockets and guns?
...
2
votes
2answers
3k views
Difference between momentum and kinetic energy
From a mathematical point of view it seems to be clear what's the difference between momentum and $mv$ and kinetic energy $\frac{1}{2} m v^2$. Now my problem is the following: Suppose you want to ...
6
votes
2answers
491 views
What are the properties of two bodies for their collision to be elastic?
For example, must the shock wave in each body be of a particular form which influences the shape and material properties of the bodies?
I suspect part of the the answer is that the objects must be ...
7
votes
9answers
845 views
How to explain independence of momentum and energy conservation in elementary terms?
I'm trying to explain to someone learning elementary physics (16 year old) that linear momentum and energy are conserved independently. I'm not a professional physicist and haven't tried to explain ...
6
votes
4answers
956 views
Examples where momentum is not equal to $mv$?
I am aware that momentum is the thing which is conserved due to symmetries in space (rotational symmetry, translaitonal symmetry, etc). I am aware that in some systems, the generalized momentum,
...
5
votes
4answers
6k views
Is pushing actually easier than pulling?
It is generally assumed that pushing a cart is more easier than pulling one. But why?
Is there any difference in terms of force required to achieve the same amount of displacement?
Or is it just a ...
