Answer:
96 ft/s
Step-by-step explanation:
We can start by deriving the equation of the velocity, which is the derivative of the position equation:
[tex]v(t) = \frac{ds}{dt} = (-16t^2)' + 800' = -32t[/tex]
After 3 seconds, the wrench would achieve a speed of
v(3) = -32t = -32*3 = -96 ft/s
So it's falling at the rate of 96 ft per second after 3 s