when u toss a rock or an object off a cliff what equation do u use to find?

Question

the velocity before it hit the ground. dont u use the change X = initial velocity * time +1/2at^2 to find the time it took. But what equation do u plug it into to find the velocity before it hits the ground????? Cuz in the problem, there tossin a rock up at a speed, dropping in it from rest, and throwing it down with a velocity.

Answer 1

A falling object conserves energy so often the easiest way to solve a problem is using 1/mv^2 =mgh
or if there is an initial down velocity 1/mv^2 -1/mv(o)^2=mgh
or if there is an initial up velocity 1/mv^2 =mg(h+H) where H is the distance traveled up before the object starts to fall I/2mv(o)^2=mgH
If time is a given then use v= v(o)+gt

Answer 2

there is what we call:

"variable acceleration" where acceleration (a = dv/dt) may be a function of v & t

"constant acceleration" where
V = Vo + at
V^2 = Vo^2 + as
S = Vot + 1/2a t^2

"free falling body" where
V = g/t
h = 1/2g t^2
V^2 = 2gh

if you do not know when of how to use these equations with different types of problem in physics then you have a problem.

the best way to undertand these is to go back to the basics or do experiments

Answer 3

VELOCITY = ACCELERATION*TIME SO SUBSTITUTE THAT IN.

ACCELERATION OF GRAVITY IS 32 F/S^2