The height at the time of a rock tossed into the
air at time from an initial height
at an initial velocity is given
by
where time is measured in seconds, height in feet, and velocity in feet per
second. The positive direction is up, so if the rock is moving down
then its velocity is negative. The magic number 16 in this equation is due
to the mass and radius of earth and would be different for example on
Mars or on the Moon. The velocity of the rock at time is given by
Suppose you throw a rock upward from a height of 64 feet with an initial velocity of 48 feet per second. The rock will hit the ground after
seconds.
Hint: