Snowball Collision!

Snowball Collision

~ Conservation of momentum through snowballs ~

To show the conservation of momentum I decided to take a video of throwing two snowballs at one another and making them hit.  It sounded like a good idea except getting the snowballs to hit wasn't as easy as it sounded.  I had my dad throw the other snowball with me.  We tried to use icy pieces of snow to avoid them completely breaking when the hit, which was sort of successful.  

Snowball Collision Take 1:

I guess my dad slightly missed the memo of hitting the snowballs and aimed too much for me... I decided to still give him another try :) 

Snowball Collision Take 2:

After taking these videos, I inserted them into Logger Pro to analyze the velocities of the snowballs to then use that information to analyze the momentum of the system.  

From the video analysis I was able to find the initial and final velocities of the two snowballs so that I could apply that to the conservation of momentum equation.  

The masses of those snowballs were 0.25 kg (V1) and 0.2 kg (V2)

Graph of Velocities:

Math for conservation of momentum:

Pi = Pf

m1v1 + m2v2 = m1v1f + m2v2f

v1-v2 = -(v1f-v2f)

0.25(-1.6) + 0.2(1.5) = 0.25(-0.77) + 0.25(2.6)

-0.4 + 0.3 = -0.2 + 0.65

1.0 = 1.3 

There is slight error, however the masses were also approximated therefore there can be room for some error.  The information from the velocities show that it is quite evident for the momentum to be conserved throughout this experiment.  

This is an elastic collision, and after calculating the initial and final KE I know that 0.2 J of KE was lost.  

KE = KF

1/2mv2 = 1/2mv2

1/2(0.25)(-1.6)2 + 1/2(0.2)(1.5)2 = 1/2(0.25)(-0.77)2 + 1/2(0.2)(2.6)2

0.32+0.225 = 0.074 + 0.676

0.545 = 0.75

= 0.75 - 0.545 

= 0.2 J