Kinetic Energy Dissipation in a Colliding System

Click For Summary

Homework Help Overview

The problem involves a collision between two hockey pucks on a smooth ice surface, where one puck is struck and deflected at an angle. The goal is to determine the fraction of the original kinetic energy of the first puck that dissipates during the collision.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss expressing kinetic energy in terms of mass and velocity, and some explore the implications of equal mass on energy calculations. There are attempts to derive the fraction of kinetic energy lost, with varying levels of clarity and confidence.

Discussion Status

The discussion includes attempts to clarify the relationship between initial and final kinetic energy, with some participants expressing confusion about the calculations. One participant claims to have found a useful equation for the problem, but there is no consensus on the correctness of the approaches discussed.

Contextual Notes

Participants are working under the assumption that the masses of the pucks are equal, which influences their calculations. There is also mention of uncertainty regarding the correct application of kinetic energy formulas.

tater08
Messages
29
Reaction score
0

Homework Statement



A hockey puck B rests on a smooth surface of ice and is struck by a second puck A , which was originally traveling at 40.0 m/s and which is deflected 30.0 degrees from its original direction. Puck B acquires a velocity at a 45.0 degree angle to the original direction of A . The pucks have the same mass.

what fraction of the orignal kinetic energy of puck A dissipates during the collision.

Homework Equations


(Delta K) /K
KE=0.5 mv^2

The Attempt at a Solution


i was able to solve for the velocity of both block a and b. But now i can't seem to figure out the original kinetic energy. I do not know where to go with the masses being the same.
Va=29.3 m/s
Vb=20.7
 
Physics news on Phys.org
You can express the kinetic energy in terms of the unknown mass "m", and go from there.
 
(Kei-Kef)/ KEi = ((1-(m1/m1+m)) KEi)/KEI = M2/m1+M2 1/ (1+1) KE should be 0.5 or 50 percent. But this is the wrong answer And I'm Totally lost. thanks for any help that i may receive.
 
I figured it out. 1-(KEf-KEi)/KEI is basically the equation to use.
 

Similar threads

Calculating Change in Kinetic Energy for a Collision on a Frictionless Air Table
  • · Replies 4 ·
Replies
4
Views
2K
Why Does Kinetic Energy Seem Lost in a Collision Despite No Friction?
  • · Replies 7 ·
Replies
7
Views
2K
Conservation of Work/Momentum of Puck Sliding Off Plate
  • · Replies 4 ·
Replies
4
Views
2K
Why Do Identically Treated Pucks Have Different Kinetic Energies?
  • · Replies 7 ·
Replies
7
Views
2K
Resistance force changing the velocity of an object
  • · Replies 8 ·
Replies
8
Views
1K
How Is Potential Energy Converted to Kinetic Energy in Physical Systems?
  • · Replies 6 ·
Replies
6
Views
1K
Work done during a collision -- Change in Kinetic Energy & change in Momentum
  • · Replies 1 ·
Replies
1
Views
2K
Energy Conservation: Puck on Wood on Frictionless Surface
  • · Replies 14 ·
Replies
14
Views
2K
Velocity and Direction of a System after Inelastic Collision
  • · Replies 2 ·
Replies
2
Views
2K
Hockey Puck Collision--momentum problem
  • · Replies 2 ·
Replies
2
Views
4K