Why do objects bounce when considering momentum and Newton's third law?

  • Thread starter Thread starter Stromthetroll
  • Start date Start date
AI Thread Summary
An object bounces due to the interaction of forces as described by Newton's third law, where the force exerted by the ground on the object can exceed the force of gravity acting downward. When a falling object impacts the ground, it compresses, creating an upward compression force that can surpass gravitational force. This results in an upward acceleration of the object after impact. The discussion emphasizes that the contact time during the impact is short, allowing for significant forces to be exerted. Understanding these dynamics clarifies why objects bounce rather than simply fall without rebounding.
Stromthetroll
Messages
6
Reaction score
0
Why does an object bounce when speaking about momentum and Newton's third law
I would like to say it is because the upward force (the force the object falling enacts on the ground and the ground acts on the object) is greater than the force of gravity, which would be impossible in an object that is dropped not thrown. My second thought is that the momentum is greater in the falling object but would that cause it to bounce and if so why? I am not asking about the elasticity or the molecular structure just bouncing and how it relates to the third law.
 
Physics news on Phys.org
Stromthetroll said:
Why does an object bounce when speaking about momentum and Newton's third law
I would like to say it is because the upward force (the force the object falling enacts on the ground and the ground acts on the object) is greater than the force of gravity, which would be impossible in an object that is dropped not thrown.

Welcome to PF.

Who says that the force the ground exerts on the object can't be greater than the force of gravity? The contact time can be very short.
 
The force the ground exerts on the object is the same as the force the object exerts on the ground third law of motion the only force downward is gravity so all of it is exerted on the ground.
 
Thanks for the welcome hopefully i don't have too many questions
 
Stromthetroll said:
The force the ground exerts on the object is the same as the force the object exerts on the ground third law of motion the only force downward is gravity so all of it is exerted on the ground.
When the ball is at its lowest point (somewhat flattened onto the ground by the impact), the lower part of the ball is under compression. So the forces acting on the mass centre of the ball are gravity down and a compression force up. The forces at the ground are the same compression down from the ball and an equal reaction from the ground. Since this compressive force exceeds gravity the ball accelerates upwards.
 
haruspex said:
When the ball is at its lowest point (somewhat flattened onto the ground by the impact), the lower part of the ball is under compression. So the forces acting on the mass centre of the ball are gravity down and a compression force up. The forces at the ground are the same compression down from the ball and an equal reaction from the ground. Since this compressive force exceeds gravity the ball accelerates upwards.

I did not even think of compression forces thank you for your aid.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Trying to understand the logic behind adding vectors with an angle between them'

Thread 'Trying to understand the logic behind adding vectors with an angle between them'

My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
View full post »

Similar threads

Blowing Into Your Own Sail
Replies
25
Views
1K
Newton's Third Law for book on a table
Replies
8
Views
3K
How do you identify the systems in which Newton's Third Law is obeyed?
Replies
6
Views
1K
Is Linear Momentum Conserved in This Case? (sliding box hits a floor tile)
Replies
2
Views
929
Understanding the Third Law of Newton — How can the forces be equal?
Replies
7
Views
2K
Kepler's Third Law vs Conservation of angular momentum
Replies
8
Views
2K
I Newton's Third Law: Action & Reaction Along the Line Connecting Two Objects
Replies
5
Views
1K
B Newton's third law (equal and opposite force)
Replies
40
Views
4K
Understanding Newton's 2nd Law of Motion
Replies
6
Views
2K
B Why Do Objects Bounce? Exploring Momentum and Energy Conservation
Replies
6
Views
1K

Hot Threads

Recent Insights

Back
Top