Initial momentum of the system

In summary, this conversation discusses the problem of conservation of momentum in a system involving two blocks with different masses and a compressed spring on a frictionless surface. The initial momentum of the system is assumed to be zero, and the speed of one block is given while the other is unknown. The conversation suggests using the equation P = m*v and applying conservation of linear momentum to solve the problem.
  • #1
bulldog23
120
0
[SOLVED] Conservation of Momentum

Homework Statement


Two blocks with masses m1 = 2.6 kg and m2 = 3.6 kg are at rest on a frictionless surface with a compressed spring between them. The spring is initially compressed by 60.0 cm and has negligible mass. When both blocks are released simultaneously and the spring has dropped to the surface, m1 is found to have a speed of 3.0 m/s. What is the speed of m2?
prob05a.gif



Homework Equations


P=m*v


The Attempt at a Solution


I am trying to figure out the initial momentum of the system, so do I m1v1=m2v2?
 
Physics news on Phys.org
  • #2
bulldog23 said:
Two blocks with masses m1 = 2.6 kg and m2 = 3.6 kg are at rest on a frictionless surface
Why do u have to calculate initial momentum? Isn't it zero!?
Yes, you may apply conservation of linear momentum, after thinking about all the forces acting on the system.
 
  • #3


I can confirm that your attempt at a solution is correct. The initial momentum of the system can be found by using the equation P=m*v, where P is the momentum, m is the mass, and v is the velocity. In this case, since the system is at rest, the initial momentum would be equal to zero. However, once the spring is released and the blocks start moving, the initial momentum will change. By applying the conservation of momentum principle, we can determine that the initial momentum of the system will be equal to the final momentum. Therefore, we can set up the equation m1v1=m2v2, where m1 and v1 represent the mass and velocity of block 1, and m2 and v2 represent the mass and velocity of block 2. Solving for v2, we get v2= (m1v1)/m2. Plugging in the given values, we get v2= (2.6 kg * 3.0 m/s)/3.6 kg = 2.17 m/s. Therefore, the speed of m2 is 2.17 m/s. This is a good example of the conservation of momentum principle, which states that in a closed system, the total momentum remains constant before and after an event.
 

What is initial momentum of the system?

The initial momentum of the system is the total momentum of all objects involved in a collision or interaction before any external forces act on the system.

How is initial momentum of the system calculated?

The initial momentum of the system is calculated by multiplying the mass of each object by its velocity and then adding all of the individual momenta together.

What is the principle of conservation of momentum?

The principle of conservation of momentum states that the total momentum of a closed system remains constant, meaning that the initial momentum of the system is equal to the final momentum of the system.

What factors can affect the initial momentum of the system?

The initial momentum of the system can be affected by the mass and velocity of the objects involved, as well as any external forces acting on the system.

Why is the initial momentum of the system important in physics?

The initial momentum of the system is important in physics because it helps us understand and predict the motion of objects in collisions or interactions. It also demonstrates the principle of conservation of momentum, which is a fundamental law in physics.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
702
  • Introductory Physics Homework Help
Replies
23
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
631
  • Introductory Physics Homework Help
Replies
16
Views
666
  • Introductory Physics Homework Help
Replies
12
Views
1K
Back
Top