An Icy Collision

An Icy Collision 

Procedure:

1. Freeze blocks of ice
2. Find the mass of ice blocks
3. Slide Small Ice block towards Large Ice Block while filming
4. Insert into Logger Pro to find velocities
5. Use conservation of momentum equations to determine results
   
   
   Video of Icy Collision:
   Note: Originally, these blocks of ice were going to collide on an icy patch of my driveway, however, the icy patch melted before I could record a decent video. So I recreated the situation with a pan of ice. 

 Photos of Ice Blocks being Weighed:

Large Block Mass: 0.340194kg M1

Small Block Mass: 0.141748kg M2

All of the Velocities are negative because the blocks of ice are traveling in the negative x-direction.

The red and blue data is for M2 (small block) and the red and green data is for M1(big block). 

*Note: the M1 initial velocity and the final velocity of M2 is 0m/s because it was not moving however on Logger Pro it is difficult to show this. 

Math for the conservation of momentum:

Pi = Pf

m1v1 + m2v2 = m1v1f + m2v2f

0.340194(0)+0.141748(-0.123)=0.340194(-0.048)+0.141748(0)

0.017435kg⋅m/s=0.016329kg⋅m/s

These numbers are almost identical and the disparity was most likely due to the bases of the ice blocks not being completely smooth resulting in some momentum being lost to friction and air resistance. In addition, the icy base was almost level, but not perfect which could have created more error.  

We can also calculate the energy of the system to determine if it is inelastic or elastic. 

1/2M1V1^2+1/2M2V2^2=1/2M1V1f^2+1/2M2V2f^2

1/2(0.340194)(0^2)+1/2(0.141748)(-0.123^2)=1/2(0.340194)(-0.048^2)+1/2(0.141748)(0^2) 

0.001072J=0.000394J

These are not equal. 

This confirms that a very tiny amount kinetic energy was in fact lost during the collision, making it inelastic because this small amount of energy was most likely converted into sound energy and the exact velocity of M2 colliding with M1 was not preserved after the collision.

KE lost = KE initial - KE final

0.000678 J =0.001072-0.000394

A total of 0.000678 Joules were lost during this collision.