



 
Hi Michelle, In the expression h=16t^{2}+vt+s the number 16 is a/2 where a is the acceleration due to gravity. a = 32 feet/sec^{2}. The force of gravity is acting downwards on the crate and hence the vertical distance is measured downwards. Thus if you make s = 0 feet then when the crate hits the ground h = 75 feet. Substituting into the expression then gives
or
The next step is to solve for t. If you need more assistance write back. Harley  


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