The Physics Behind the Age Old Snowball Fight
The Breakdown of a snowball
Have you ever wondered how thousands of microscopic flakes of frozen water could stick together to be launched through the air at high velocities? Or how about the fact that the colder it gets, the harder it is to craft a snowball. Well the reason behind these two things has to do with the key ingredient of a snow ball: water. Water is unique in the fact that it is more dense in its liquid form than its solid form. This allows for the snow to be compressed and welded into a ball. What really happens during this process is that as the snow is compressed by the holder, the pressure exerted on the ball melts the snow into its liquid state of water. When released, the water refreezes fusing itself together with the other snow around it. This is the reason why a snowball cannot be made on a really cold day; there is no presence of liquid water to allow the snow to be compressed so that it can stick to the other snowflakes.
Collision of a Snowball
The collision of a snowball can range from perfectly inelastic to just inelastic depending on the object it is hitting. If it happens to hit something like another pile of snow, it may combine with it to form a new object. This would be a perfectly inelastic collision. However, this would be very unlikely since snowballs usually fall apart on contact. Therefore, it would result in just a inelastic collision that would fall in a rather large range depending on the circumstances.
The Experiment
Part 1: Projectile Motion of the snowball
The overall motion of the snowball was right and downwards. This is due to the forces that were acting on the ball while it was in the air. The first, gravity caused it to move downwards. The second, air resistance, caused the ball to slow down in the x direction.
Velocity VS Time of the Snowball
Velocity of Snowball before collision with target:
10.127 m/s
Part 2: Collision With Target
Calculating Final Velocities of Snowball and Target
Mass of Snowball: .028kg
Mass of Target: .168 kg
Initial Velocity: 10.127 m/s
Change in height of Frisbee = .21844 m
Velocity of Frisbee after collision
1/2 m v^2 = mgh
1/2 * v^2 = 9.8 * .21844
Final Velocity of Frisbee = 2.06916 m/s
m1 * v1i + m2*v2i = m1 * v1f + m2*v2f
.028 * 10.127 + 0 = .028 * v1f + .168 * 2.06916
.283556 = .028 * v1f + .347619
v1f = -.06406/.028
Final Velocity of Snowball = -2.28796 m/s
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