(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Three balls which have equal masses are fired with equal speeds. One ball is fired up at an angle of 45 degrees, the other is fired up at an angle of 60 degrees, and the third ball is fired straight up at an angle of 90 degrees from the horizontal surface. Rank in order, from largest to smallest, their speeds Va, Vb, and Vc as they cross a dashed horizontal line approximately a couple meters away from the balls. Explain. (All three are fired with sufficient speed to reach the line.)

2. Relevant equations

3. The attempt at a solution

I believe that Va=Vb=Vc because free fall, which is what they seem to be in, only depends on the vertical velocity, and since this is the same for all three speeds, as they differ only with their horizontal velocities, and also since they have the same free fall acceleration (9.8 m/s^2) they will reach the horizontal line with the same speed. The reason why I think I am not getting this right, is because this question is taken out from the energy chapter (chapter 10) and I did not use the energy laws to figure this out.

Any help?!

Thank-you!

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# Balls fired up in air, find their speeds

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