a stone is thrown vertically upward with an intial velovity of 12m/s, after some time it returns to the same position
a)what is the displacement of the stone
b)the highest point it reached if it took 2 seconds for the stone to reach this point
c)the kinetic energy of the stone
d)the potential energy of the stone at the highest point
a)
Displacement is the vector from the start point to the finish point.
We ended up where we started.
So
ZERO !!!! (this was a trick question)
b)
I guess we do not know that g = 9.81 m/s^2 or we would not need that 2 seconds given.
v = Vi - g t
at top v = 0
Vi = g t = 2 g
12 = 2 g
g = 6 m/s^2 (some other planet)
but anyway
h = Hi + Vi t -(1/2)g t^2
h = 12 (2) -(1/2)(6)(4) = 24 -12
h = 12 meters on this planet
c) the max Ke = (1/2)(m)(12)^2
= 72 m
d) max Pe above the thrower
= m g h = m (6)(12) = 72 m
of course because max Ke = max Pe
This question is very strange. Did you get it from a text or did you make it up?