math
posted by dan on .
an object released from rest will fall 16t^2 feet, t seconds after it is dropped. 2 pebbles are dropped, one after the other, from a cliff that is 64 feet high. the 2nd pebble is released the instant the first pebble has fallen exactly one foot. how far above the ground is the second pebble when the first pebble strikes the ground?

1st pebble falls 1 foot in 1/4 sec
1st pebble takes 2 seconds to hit
during 7/4 seconds, second pebble falls 49 feet
so it is still 11 feet up when the first pebble hits 
is there an equation for this?

I don,t know that what I am trying to firgure that oug. I even looked in a math book. Nothing.
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