Answer:
They are the same (assuming there is no air friction)
Explanation:
Take a look at the picture.
When the first ball (the one thrown upward) gets to the point marked as A, the speed will has the exact same value V but the velocity will now point downward (just like the second ball).
So if you think about it, the first ball, from point A to the ground, will behave exactly like the second ball (same initial speed, same height).
That is why the speeds will be the same when they reach the ground.
Answer:
Velocity is same
Explanation:
Case I:
When the ball throws upwards
Let the velocity of the ball as it hits the ground is V'.
Initial velocity, u = V
Final velocity, v = V'
height = h
acceleration due to gravity = g
Use third equation of motion
[tex]v^{2}=u^{2}+2as[/tex]
By substituting the values
[tex]V'^{2}=V^{2}+2(-g)(-h)[/tex]
[tex]V'=\sqrt{V^{2}+2gh}[/tex] .... (1)
Case II:
When the ball throws downwards
Let the velocity of the ball as it hits the ground is V''.
Initial velocity, u = V
Final velocity, v = V''
height = h
acceleration due to gravity = g
Use third equation of motion
[tex]v^{2}=u^{2}+2as[/tex]
By substituting the values
[tex]V''^{2}=V^{2}+2(-g)(-h)[/tex]
[tex]V''=\sqrt{V^{2}+2gh}[/tex] .... (2)
By comparing the equation (1) and equation (2), we get
V' = V''
Thus, the velocity of balls in both the cases is same as they strikes the ground.
