Solving Collisions: Homework Help

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In summary, the conversation discusses the problem of determining the velocity of two blocks after a collision. The solution involves using the principle of conservation of kinetic energy and momentum to set up simultaneous equations and solve for the velocities. The person solving the problem admits to guessing at first, but then provides their calculations for the final answer.
  • #1
coffeem
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Homework Statement



[PLAIN]http://img834.imageshack.us/img834/8045/questuinfunny.jpg

The Attempt at a Solution



[PLAIN]http://img824.imageshack.us/img824/3619/funnyquestion.jpg
 
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  • #2
Tell me why you think you can assume that each piece gets the same amount of energy?
 
  • #3
6Stang7 said:
Tell me why you think you can assume that each piece gets the same amount of energy?

Im not going to lie. I guessed. Wish to give me a better idea of how to tackle this?
 
  • #4
What is the definition of an elastic collision?
 
  • #5
6Stang7 said:
What is the definition of an elastic collision?

Ah...

so what I have done is conserves ALL of the kinetic energy! This let's me set up some simultaneous equestions with the momentum and all the kinetic energy conserved.

This gives me: v1 = 254.4m/s

and v2 =46.2 m/s.

does this seem correct (i havnt got the answer!) i can post all the workings if that helps.
 
  • #6
Go ahead and post the work.
 

1. How do I calculate the final velocity of an object after a collision?

In order to calculate the final velocity of an object after a collision, you will need to use the conservation of momentum equation: m1v1i + m2v2i = m1v1f + m2v2f. This equation states that the total momentum before a collision is equal to the total momentum after the collision. Simply plug in the values for the initial velocities and masses of the two objects and solve for the final velocity of the object you are interested in.

2. What is the difference between elastic and inelastic collisions?

Elastic collisions are those in which both kinetic energy and momentum are conserved. In these collisions, the objects involved bounce off of each other with no loss of energy. Inelastic collisions, on the other hand, are those in which kinetic energy is not conserved. In these collisions, some of the kinetic energy is converted into other forms, such as heat or sound.

3. How do I calculate the coefficient of restitution for a collision?

The coefficient of restitution, or e, is a measure of the elasticity of a collision and is calculated by taking the ratio of the relative velocity after the collision to the relative velocity before the collision. This can be written as e = v2f - v1f / v1i - v2i. The value of e will always be between 0 and 1, with 1 representing a perfectly elastic collision and 0 representing a completely inelastic collision.

4. What is the difference between a one-dimensional and a two-dimensional collision?

In a one-dimensional collision, the objects involved are moving in a straight line and no forces act on them in any direction other than the line of motion. In a two-dimensional collision, the objects are moving in a plane and may experience forces in multiple directions, such as gravity or air resistance. This adds an extra level of complexity to the calculations involved in solving the collision.

5. How do I account for external forces in a collision calculation?

External forces, such as friction or air resistance, can have an impact on the outcome of a collision by changing the momentum of the objects involved. In order to account for these forces, you will need to use the impulse-momentum equation: FΔt = mΔv. This equation relates the force applied to an object over a certain time interval to the change in its momentum. By solving for Δv, you can determine how the external forces have affected the velocity of the objects in the collision.

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