- #1
Simoncoolstan
- 8
- 0
Homework Statement
A 0.30kg puck A, moving at 5m/s [W], undergoes a collision with a 0.40 puck B which is initially at rest. Pick A moves off at 4.2m/s [W 30deg N]. Find the final velocity of Puck B.
Homework Equations
pi=pf
mvi=mvf
The Attempt at a Solution
Let [N] and [W] be positive
Puck A
vix = 5m/s
m1= 0.30kg
vf=4.2m/s
vfx : 4.2cos30=3.6m/s
vfy : 4.2sin30=2.1 m/s
Puck B
vi=0m/s
m2=0.40kg
Solve for v2fx
m1v1ix + m2v2ix = m1v1fx + m2v2fx
(0.30)(5)+(0.40)(0)=(0.30)(3.6)+(0.40)v2fx
2.43= v2fx
Solve for v2fy
m1v1iy + m2v2iy = m1v1fy + m2v2fy
(0.30)(0)+(0.40)(0)=(0.30)(2.1)+(0.40)v2fy
-1.58 = v2fy
Find the resultant v2f
|v2f| = sqrt((2.43)2+(1.58)2)
|v2f| = 2.9 m/s
tantheta = (1.58/2.43)
theta = tan-1(1.58/2.43)
theta = 33deg
Final answer: velocity of Puck B is 2.9m/s [33deg SW].
Can someone tell me if I'm doing this correctly?:
Last edited: