Projectiles
https://drive.google.com/file/d/0B3QmdB5-KJ7uZXdpTHJ2VWJncnVTLVRPVzNSZ0dyX0lqcUdF/view?usp=sharing
Was air resistance noticeable?
Air resistance pulls in the opposite direction of the velocity, which is seen the following diagrams. We know that air resistance is a part of the system, but it is not be strong enough to be noticeable.
The best line of fit for the x-velocity vs time graph is generally horizontal. Therefore, air resistance isn't noticeable. If air-resistance was noticeable then the best line of fit for the x-velocity vs. time would have a negative slope. Also since the initial and final x velocity are the same, there was no apparent effect of air resistance on the tennis ball.
Was energy conserved?
Energy was not conserved. We can determine this by looking at the initial and final kinetic and potential energy.
The total mechanical energy is the sum of the kinetic energy and gravitational potential energy. Since the total mechanical energy is greater initially than at the final moment, energy wasn't conserved. If energy had been conserved then the net energy would be 0, but in this motion, it is negative. It could have transferred through heat or sound.
Was momentum conserved?
The y-momentum isn't conserved because as seen in the graph above, the final velocity is less than the initial velocity. Since the velocity differs while the mass remains constant, the momentum was not conserved.
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The x-momentum is conserved as seen in the graph above. This conserved momentum is because the initial and final velocity are the same. Since the velocity and mass are constant then the momentum would be conserved.
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