at what height from the top of the building when the stone rise?

Question

a man of the top of the building 100m height throws a stone vertically upward with an initial velocity 6.0m/s.how long after it is thrown willit take the stone to hit the ground?show ur solution?

Answer 1

u can also solve this by takin s= -100m
n by the formula S= ut + 1/2 gt^2
g = 9.8m/s^2. u = -6m/s .......4 the 2nd part
and

find time of the 1st half by the formula
=> v = u + at....[ where u = 6m/s, v = -6m/s(velocity in oposit direction)]

ALSO REMEMBER THAT WEN A TRAJECTORY AGAIN REACHES ITS STARTIN PT. IT HAS THE SAME MAGNITUDE OF VELOCITY

-ve sign is given to all dat is below the level or in the direction below the startin point
combine these 2................ n voila..
with time u can master this easy.... n logical method

Answer 2

The time to zero velocity is 6.0/9.8 = .612 seconds by using at = v, then the height above the building at which this happens is 1.835 meters by using a(t^2)/2 = d so now the stone must drop 101.835 meters. Solving a(t^2)/2 = d for t give a t of 4.559 seconds. So the total time is 4.559 + .612 = 5.171 seconds.