Question

The boy on the tower of height h = 16 m in the figure below throws a ball a distance of x = 64 m, as shown. At what speed, in m/s, is the ball thrown?

Answer 1

there are two motions , down ward motion and horizontal motion horizontal motion--there is no acceleration , boy throws the ball with a velocity u
vertical motion-- no initial velocity , there is acceleration due to gravity

now for vertical motion the distance covered is the height 16 m under the influence of gravity we know
s=ut+1/2 at^2
s= distance here 16 m
u = initial velocity here 0 m/s
t= time in seconds
a= acceleration here it's 9.8 m/s^2
16=1/2*9.8 t^2
16/4.9= t^2
t=1.807 seconds
in this time the ball covers a horizontal distance of 64 m
S=ut+1/2 at^2 f
or this case
u??
a=0
s=64 m
t=1.807 seconds
64=u*1.807
u=35.417 m/s
this is the initial velocity of the ball