Finding the impulse of a hockey puck colliding with a wall

by waldosa
Tags: colliding, hockey, impulse, puck, wall
waldosa is offline
Feb12-11, 01:13 PM
P: 2
1. The problem statement, all variables and given/known data

A 261 g hockey puck is sliding on ice with a speed of 5.34 m/s hits a wall at an angle of 27.3 to the wall and bounces back at the same angle with the same speed.

a) If the wall and the hockey puck are in contact for 10.9 ms, find the magnitude of the impulse on the puck.
b) Calculate the average force exerted by the puck on the wall.

2. Relevant equations
J = F*∆t = ∆p
p = m*v
a = ∆v/∆t

3. The attempt at a solution

a) I assumed that velocity in the x is not changing, and thus ∆Vx = ∆px = 0. Based on that, I assumed that any impulse/change in momentum, can be calculated from the y-component.

Jy = J = m*∆Vy
= m(Vfy - Viy) _____ Viy = -Vfy
= m (2Vfy)
=2*m*Vfy = (2)(0.261)(5.34 sin 27.3)
J = 2.306 kg*m/s

however, it says that this answer is incorrect. I'm not sure where i'm going wrong, as only the initial and final velocities in the y are changing, and thus Jy = J.

b) I'm assuming that the average force can be calculated via J = F*∆t, as i don't have the correct magnitude of the impulse yet, I haven't been able to calculate it correctly
Phys.Org News Partner Science news on
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
gneill is offline
Feb12-11, 01:47 PM
P: 11,440
Check your calculator for the degree/radian setting!
waldosa is offline
Feb12-11, 02:20 PM
P: 2
Wow I can't believe I missed that, thanks!

Register to reply

Related Discussions
Hockey puck striking a wall Introductory Physics Homework 19
Collision with ice hockey puck Introductory Physics Homework 5
Finding the mass of a hockey puck - inertia!!! Introductory Physics Homework 2
Hockey Puck Introductory Physics Homework 5
hockey puck Introductory Physics Homework 1