how many feet can a pebble fall in 4 seconds

Answer 1

general equation

is d(t) = -16t^2 + vot + ho

where t = time in seconds, d = distance in feet, vo= initiall velocity, in feet per second, ho = initial height in feet, and the squared term is the effect of gravity which causes objects to fall at 32 feet per second, per second, at sea level. the -16t^2 term is actually a close approximation, rounded off to nearest integer. more accurate number is 32.174 feet per second per secon which makes the squared t term have a coefficient of - 32.174/2 = - 16.087

if vo = 0

the pebble will fall -16(4)^2 = -256 feet in 4 seconds

or more accurately -16.087(16 = 257.392 feet in 4 seconds