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Homework Help: Projectile motion - time taken to hit the ground

  1. Jan 5, 2005 #1
    Can someone please explain to me why the time it takes for an object to drop down is the same time it takes to hit the ground if you throw it?

  2. jcsd
  3. Jan 5, 2005 #2
    It depends how you throw it. If you throw it straight down, obviously it will fall faster in that case than it will if you just drop it. However, if you drop it horizontally, then it will take the same amount of time. This is because you can think of the object as moving in two directions, horizontally and vertically. In terms of the horizontal, you can tell what will happen. If you drop it, it doesn't travel horizontally. But, if you look at the vertical motion, there is no difference at all. Initially, it started with the same velocity going downwards (0) and it has the same acceleration (g). So they must fall down in the same amount of time. Vertical and Horizontal motion are completely independant.
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