Two Hockey Puck Collision: Calculating Speed After Impact

AI Thread Summary
Two hockey pucks of equal mass collide, with one initially moving at 5.4 m/s and the other at rest. After the collision, the pucks move at angles of 33 and 46 degrees relative to the initial puck's direction. The correct speeds after the collision are determined to be 3 m/s and 4 m/s. Momentum conservation is crucial, as it is a vector quantity, requiring the final momentum to equal the initial momentum in both magnitude and direction. The use of vector analysis, such as the sine law, helps in solving for the final speeds.
Morhas
Messages
22
Reaction score
0

Homework Statement


Two hockey puck of equal mass undergo a collision on a hockey rink. One puck is initiall at rest while the other is moving with a speed of 5.4m/s. After the collision, the velocities of the pucks make angles of 33 and 46 (degrees) relative to the initial velocity of the moving puck. Determine the speed of each puck after the collision.


Homework Equations





The Attempt at a Solution



We have tried several failed approaches. The correct answer is 3m/s and 4m/s. What is confusing us is that the momentum should be conserved. So the sum of the two final momentums should be that of the initial momentum. Thanks in advance,
 
Physics news on Phys.org
Bump. Can anyone explain this? My friend and I have a test tommorow and we still don't see how this is possible. Thanks.
 
Morhas said:
Bump. Can anyone explain this? My friend and I have a test tommorow and we still don't see how this is possible. Thanks.
It is conserved. momentum is a vector quantity. The initial momentum is to the right. The final momentum, the vector sum of the 2 pucks after the collison, must be equal to and in the same direction as the initial momentum.
 
Ahhh I see. So What I've done is drawn the two vectors as two sides in a triangle, with the third side being the initial momentum vector. Then I solved with sin law. Thanks for the post!
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Collision problem: Two hockey pucks collide and stick together....
Replies
4
Views
2K
What Are the Final Velocities of Hockey Pucks After a Glancing Collision?
Replies
4
Views
3K
How Do You Calculate the Momentum of a Puck After a Collision?
Replies
5
Views
3K
Collision of Equal Mass Hockey Pucks
Replies
1
Views
3K
Collision of Hockey Pucks: Solving for Final Speed and Angle
Replies
35
Views
5K
Hockey Puck Collision--momentum problem
Replies
2
Views
4K
Conservation of Angular momentum and linear momentum
Replies
7
Views
5K
Momentum After Inelastic Collison
Replies
1
Views
1K
Calculating Change in Kinetic Energy for a Collision on a Frictionless Air Table
Replies
4
Views
1K
Solve for 2D Elastic Collision: Find θ & φ Angles
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top