Practice Problems: Free Fall
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1. A rock is dropped from a garage roof from rest.  The roof is 6.0 m from the ground.
a. (easy) Determine how long it takes the rock to hit the ground.
b. (easy) Determine the velocity of the rock as it hits the ground.
c. (moderate) A second rock is projected straight upward from ground level at the moment the first rock was released.  This second rock had an initial upward velocity of +6.0 m/s.  How long will this second rock take to reach maximum height?
d. (hard) At what time after release will the two rock have the same height?

2. (moderate) A projectile is shot upward at 189 m/s from a height of 20 m off the ground. How long will it take for the projectile to be at ground level?

3. (moderate) A hot-air balloon is hovering over a large public park. The operator of the balloon then makes the balloon begin to rise at a constant rate of 0.8 m/s. At some height from the ground the operator drops a rock from the basket. The rock take 10.3 seconds to hit a target on the ground. How high (above the ground) was the rock when it was released and what was its maximum height?

Please supplement these problems with those found in your companion text.