If a construction worker drops a wrench
from the top of a building 375 feet high the
wrench will be
s(t) = −16t2 + 375
feet above the ground after t seconds.
determine the velocity of the wrench 4 seonds after it was was dropped.

answer in units of ft/sec

To find velocity at a given moment, also known as instantaneous velocity, we need to know how to take the derivative of an equation;
you can take the derivative of s(t)=62t^2+ 375 by first moving the 2 in front of 162 and multiply both which well give you 324t and 375 will turn to 0
-16t^2 results in -32t
so our velocity at t=4 is -32(4) = -128ft per second