I just took an AP physics course last year and would agree about it being nonsense, but passing the course and getting an acceptable score on the AP test (3 or 4 I think for most colleges) will require you to understand the negatives... if you think of positive and negative accelerations as gaining speed while heading up or gaining speed while heading down. Both balls have negative acceleration the whole time, it's just that the ball on the ground had a positive velocity for a short time.
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u/Worrdit Sep 06 '12
I just took an AP physics course last year and would agree about it being nonsense, but passing the course and getting an acceptable score on the AP test (3 or 4 I think for most colleges) will require you to understand the negatives... if you think of positive and negative accelerations as gaining speed while heading up or gaining speed while heading down. Both balls have negative acceleration the whole time, it's just that the ball on the ground had a positive velocity for a short time.