A disk of mass 0.500 kg approaches 2.00 m / s towards another similar disk that is found at rest on ice without friction. After the crash, the first disc comes out with speed v1\' forming an angle of + 30.0 ° with respect to the original line of movement and the second disc comes out with speed v2\' to -60.0 ° with respect to the same line. a) Calculate the velocities v1\' and v2\' of the discs after the collision. b) Was the collision elastic? Why? 05kg Solution using conservation of momentum along the Y-direction 0 = m v 1 \' Sin30 - m v 2 \' Sin60 v 1 \' Sin30 = v 2 \' Sin60 v 1 \' = 1.73 v 2 \' eq-1 using conservation of momentum along the X-direction m v = m v 1 \' Cos30 + m v 2 \' Cos60 2 = v 1 \' Cos30 + v 2 \' Cos60 2 = (1.73 v 2 \' ) Cos30 + v 2 \' Cos60 v 2 \' = 1 m/s using eq-1 v 1 \' = 1.73 v 2 \' = 1.73 x 1 = 1.73 m/s yes the collision is elastic .

1. A disk of mass 0.500 kg approaches 2.00 m / s towards another similar disk that is found at rest
on ice without friction. After the crash, the first disc comes out with speed v1' forming an angle
of + 30.0 ° with respect to the original line of movement and the second disc comes out with
speed v2' to -60.0 ° with respect to the same line. a) Calculate the velocities v1' and v2' of the
discs after the collision. b) Was the collision elastic? Why?
05kg
Solution
using conservation of momentum along the Y-direction
0 = m v 1 ' Sin30 - m v 2 ' Sin60
v 1 ' Sin30 = v 2 ' Sin60
v 1 ' = 1.73 v 2 ' eq-1
using conservation of momentum along the X-direction
m v = m v 1 ' Cos30 + m v 2 ' Cos60
2 = v 1 ' Cos30 + v 2 ' Cos60
2 = (1.73 v 2 ' ) Cos30 + v 2 ' Cos60
v 2 ' = 1 m/s
using eq-1
v 1 ' = 1.73 v 2 ' = 1.73 x 1 = 1.73 m/s
yes the collision is elastic