Discounting air resistance, the height (in feet) above the earth for a shy diver t seconds agter jumping from an airplane at 10,000 ft would be given by the following
H=-16t(t is squared)+10,000
FInd the time it would take the sky diver to reach the ground.

Plug in 0 for H, solve for t.

There should be nothing hard here...

Move the 10000, move the 16, square root it. Then just pop it into your calculator.

Ask if you need more help than that.