Juggling Problem: Solving for Time, Speed & Height

[joeth04]

Homework Statement

John is practicing juggling three balls at once. He determines that he can perform this act, so long as there is a 4 s interval between the time when a ball leaves one of his hands and the next ball in one of his hands. (seems like the wording is messed up)
a)How long must each ball be in the air before it returns to John's hand?
b) At what speed must John throw each ball upward for its travel to require the time you calculated for part (a)?
c)How high above John's hands must each ball go?

Homework Equations

V=Vo+at
X=Xo+Vot+1/2(a)(t^2)
V^2=Vo^2+2a(X-Xo)

 

[LowlyPion]

Homework Statement

John is practicing juggling three balls at once. He determines that he can perform this act, so long as there is a 4 s interval between the time when a ball leaves one of his hands and the next ball in one of his hands. (seems like the wording is messed up)
a)How long must each ball be in the air before it returns to John's hand?
b) At what speed must John throw each ball upward for its travel to require the time you calculated for part (a)?
c)How high above John's hands must each ball go?

Homework Equations

V=Vo+at
X=Xo+Vot+1/2(a)(t^2)
V^2=Vo^2+2a(X-Xo)

Ok. How would you break up the problem?

How long does 1 ball have to be in the air?

With that time how high does it have to go? And what velocity does John have to give it?

 

[joeth04]

i don't even understand what this statement is trying to say: "between the time when a ball leaves one of his hands and the next ball in one of his hands"

 

[LowlyPion]

i don't even understand what this statement is trying to say: "between the time when a ball leaves one of his hands and the next ball in one of his hands"

It means that 4 seconds elapses before he catches another ball. There are 3 balls, so how many must be in the air at anyone time? If there is 4 seconds between each then the flight time of one ball must be ...?