All Questions
34
questions
4
votes
2
answers
756
views
After how many bounces will a ball's mechanical energy equal zero?
This was a question I asked myself for fun. It turned out to be more difficult than I initially imagined.
The Problem: Let's say a ball is dropped from h0. Air friction is negligible. The collisions ...
- 117
-1
votes
1
answer
36
views
Momentum conservation and collisions [duplicate]
Whenever a collision happens on a rough horizontal surface, because the frictional force will be external to the system, momentum wont be conserved. However, can we consider the friction to be ...
0
votes
2
answers
42
views
Are Coefficients of Kinetic Friction Additive?
Question setup:
Say we have two blocks on a $30^{\circ}$ incline plane with masses $4\ kg (A)$ and $8\ kg (B)$.
The coefficient of kinetic friction between block $A$ and the plane is $0.25$, and that ...
- 3
0
votes
1
answer
31
views
Car vs Tricycle getting rear ended
Suppose you have a car sitting stationary. Then it gets rear ended by a truck going at $x$ speed.
Then you have a tricycle with the same size wheels and same weight. It also gets hit by a truck also ...
1
vote
1
answer
49
views
Energy Loss of a Ball which Splits into Pieces
It is well-known that one can analyse the loss of kinetic energy when an inelastic ball falls and bounces back up from the ground in terms of the coefficient of restitution
$$E_f - E_i= \frac{K_i - ...
- 1,410
0
votes
0
answers
41
views
How Does Angular Momentum Affect the Angle of Reflection of a Puck Bouncing Off a Wall?
I am trying to understand the relationship between angular momentum and the angle of reflection when a puck bounces off a wall. More specifically, I am curious about the role that the coefficient of ...
- 1
0
votes
1
answer
50
views
Is total Mechanical Energy Conserved in an inelastic collision with negligible friction?
I understand that in an inelastic collision, mechanical energy is lost to heat, sound, deformation, etc. However, if there is no friction between the two objects that collide or the two objects with ...
23
votes
3
answers
7k
views
How is this child able to move their crib while standing inside of it?
I was scrolling Instagram and saw this Reel which at first was normal but when I started to think how the child was able to move then I got confused. The video shows a child standing inside of a crib ...
- 8,230
1
vote
1
answer
261
views
Relationship Between Coefficient of Friction and Coefficient of Restitution [closed]
Is there a formula that relates the coefficient of friction, specifically kinetic friction, with the coefficient of restitution?
- 13
2
votes
3
answers
649
views
Role of friction in bouncing
I am trying to simulate a ball bouncing on an inclined surface. And I am thinking about how friction play during the collision.
When there is no friction, at collision, we can exclude the force to ...
- 31
0
votes
2
answers
132
views
Momentum Conservation during Collision
Is momentum really conserved when two bodies collide?
What about friction between the 2 bodies during collision and between the bodies and the ground?
Does friction become internal force here?
I just ...
- 31
1
vote
1
answer
119
views
A cylinder doing pure rolling in the front collides
Consider a cylinder rolling in the forward direction with velocity of $v$ and angular velocity of $v/r$. There is a wall in front and the cylinder collides with the wall. The collision is perfectly ...
- 33
1
vote
1
answer
48
views
Roll, slip, or bounce?
A sphere is dropped onto an infinite inclined plane. Can we predict whether the sphere rolls, slips, or bounces after hitting the surface? If so, how can we predict this?
user290768
0
votes
1
answer
84
views
If you swing anything fast enough, can you nail a nail?
You have a nail set in a piece of wood for example. Theoretically if you swung something else at it, no matter what it was, could you drive the nail in, if it were moving fast enough. I get that the ...
1
vote
1
answer
154
views
What lies between "perfectly smooth" and "perfectly rough"?
In elastic collisions of spheres, there are two approximations that can be made: Either they are perfectly smooth, and you ignore the rotation component, or they are perfectly rough and the rotation ...
- 381