Answer:
u=78.4m/s
Explanation:
A ball is thrown vertically upward, which is the positive direction.A little later it returns to its point of release.The ball is in the air for a total time of 8.0 s.What is its initial velocity? Neglect air resistance
from newtons equation of motion
s=ut[tex]+\frac{1}{2}at^{2}[/tex]
v=u+at
v=0 because at maximum height reached by the ball the ball stops moving
0=u-9.8*8
u=78.4m/s
u=initial velocity
v=final velocity
a=acceleration due to gravity, 9.81m/s^2
t=time it takes in air
s= distance to get to the maximum before returning
