(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] Finding time up and time down: Verticle Projectile

Hey guys, so I have a take home lab that is just murdering me...

Imagine a vertical projectile launcher that sits on the ground, that shoots a ball up in the air and lands back in the projectile.

The knowns are:

distance from the top of the projectile launcher to the top of the ball's flight = 0.5m

distance of the compressed spring = .033m

and mass of ball = .00965kg

Now, I thought time down could be gotten using Sqrt(2 * d/ g), which would be Sqrt(2 * .5m/9.8) = .319 seconds, but the professor marked that wrong.

Other than that, I know that V_i = 0 when the ball is at the top of it's flight. So I decided to get V_f by using V_f = Sqrt(2 * g * d), which is Sqrt(2 * 9.8 * .5m) = 3.13 seconds. But I don't know how I can get time down using those two.

Also, I "figure" time down would be the same as time up. With that said, if the initial velocity is 3.13m/s and the final velocity is 0m/s for the time up, then V_f - V_i / g

= 0 - 3.13 / 9.8 = 3.19s . That's what I got for my time down on my paper, so if time up is = to time down, and I got my time down marked wrong when it was .319, then both aren't .319 :(

Edit: Err, but then wouldn't the force of the spring be a factor? I'm so confused...

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# Homework Help: Finding time up and time down: Verticle Projectile

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