A stone is thrown vertically upward from the top of a house 60 feet above the ground with the initial velocity of 40 ft/sec.
a) At what time will the stone reach its maximum height?
b) What is its greatest height?
c) How long will it take the stone to pass the top of the house on its way down?
d) What is the velocity at that instant?
e) How long will it take the stone to strike the ground?
f) What is the velocity when it strikes the ground?
2007-10-07 08:14:07 · 1 answers · asked by daaznone90 2 in Science & Mathematics ➔ Mathematics
From the top of the house
h=-16t^2 +40t
h´= -32t+40 = 0 so t = 40/32= 5/4 s
hmax = 25 feet above the top
c)from h max 5/4 s
d) from h max the equation is h = 16 t^2 and v= 32t (downwards)==32(5/4)=40feet/s
e) 85 = 16 t^2 so t = 1/4 sqrt(85) and
f) v= 8*sqrt(85)
2007-10-07 10:48:33 · answer #1 · answered by santmann2002 7 · 0⤊ 0⤋