Question about momentum and kinetic energy

In summary, kinetic energy is calculated by multiplying velocity squared by mass, while momentum is calculated by multiplying velocity and mass. This is because conservation of kinetic energy is linked to symmetry in the motion of time, while conservation of momentum is linked to symmetry in the motion of space. To understand this further, you can search for Noether's theorem on PF, where you will find many discussions on the subject.
  • #1
larsa
47
2
First of all i am not a native speaker so i apologize for my english.
Kinetic energy is velocity squared multiplied by mass, whereas momentum is just velocity multiplied by mass.
I have read that the reason for this is because conservation of kinetic energy is related to symmetry of the motion in time and conservation of momentum is related to the symmetry in the motion of space.
Could someone give an intuitive or not explanation about this?

Thank you in advance
 
  • Like
Likes PeroK
Physics news on Phys.org
  • #2
Do a search on Noether's theorem on PF. You will find many thread discussing the subject.
 
  • #3
DrClaude said:
Do a search on Noether's theorem on PF. You will find many thread discussing the subject.
What i don't understand is how velocity squared is related to symmetry. I have not found any explanation about this. I will look again, thanks
 
  • #4
larsa said:
First of all i am not a native speaker so i apologize for my english.
Kinetic energy is velocity squared multiplied by mass, whereas momentum is just velocity multiplied by mass.
I have read that the reason for this is because conservation of kinetic energy is related to symmetry of the motion in time and conservation of momentum is related to the symmetry in the motion of space.
Could someone give an intuitive or not explanation about this?

Thank you in advance

There is no need to apologise for your near perfect English!
 

Related to Question about momentum and kinetic energy

1. What is momentum?

Momentum is a measure of an object's motion and is calculated by multiplying its mass by its velocity. It is a vector quantity, meaning it has both magnitude and direction.

2. How is momentum calculated?

Momentum is calculated by multiplying an object's mass (m) by its velocity (v). The formula for momentum is p = m * v.

3. What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is directly proportional to the mass and square of the velocity of an object and is a scalar quantity.

4. How is kinetic energy related to momentum?

Kinetic energy and momentum are both measures of an object's motion. Kinetic energy is calculated using mass and velocity, while momentum is calculated using mass and velocity as well as direction. The two are related by the equation KE = 1/2 * m * v^2, where m is mass and v is velocity.

5. Can momentum and kinetic energy be conserved?

Yes, momentum and kinetic energy are both conserved in a closed system. This means that in the absence of external forces, the total amount of momentum and kinetic energy will remain constant. This is known as the Law of Conservation of Momentum and Energy.

Similar threads

Replies
3
Views
1K
Replies
34
Views
2K
Replies
19
Views
1K
Replies
12
Views
1K
Replies
16
Views
1K
Replies
5
Views
888
  • Mechanics
2
Replies
53
Views
2K
Replies
11
Views
1K
Replies
7
Views
805
Back
Top