What Is the Velocity of the First Car After the Collision?

  • Thread starter Thread starter physicsgurl12
  • Start date Start date
  • Tags Tags
    Collision Velocity
Click For Summary
SUMMARY

The discussion focuses on calculating the velocity of the first car after a collision using the law of conservation of linear momentum. Given a 480 kg car moving at 14.4 m/s collides with a 570 kg car moving at 13.4 m/s, the final velocity of the first car is determined to be 8.94 m/s. The equation used is m1u1 + m2u2 = m1v1 + m2v2, where m1 and m2 are the masses of the cars, and u1 and u2 are their initial velocities.

PREREQUISITES
  • Understanding of linear momentum
  • Familiarity with conservation laws in physics
  • Basic algebra for solving equations
  • Knowledge of mass and velocity units (kg, m/s)
NEXT STEPS
  • Study the principles of conservation of momentum in elastic and inelastic collisions
  • Learn how to apply momentum equations in multi-object collision scenarios
  • Explore real-world applications of momentum conservation in vehicle collisions
  • Investigate the effects of mass and velocity on collision outcomes
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and collision theory, as well as educators seeking to explain momentum conservation in practical scenarios.

physicsgurl12
Messages
184
Reaction score
0

Homework Statement



a 480kg car moving at 14.4m/s hits a another car from behind moving at 13.4m/s in the same direction. if the second car has a mass of 570kg and a new speed of 17.9m/s what is the velocity of the first car after the collision??

Homework Equations



m1*v1=m2*v2
doubt that's it

The Attempt at a Solution


i know its 8.94m/s but why??
 
Physics news on Phys.org
You have to use the law of conservation of linear momentum. According to this law, the total momentum before collision is equal to the total momentum after collision..
So m1u1 + m2u2 = m1v1 + m2v2.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
8K
  • · Replies 13 ·
Replies
13
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
5
Views
3K
Replies
3
Views
1K