What is the Vertical Separation of Steel Balls in a Steady Fall?

[Larrytsai]

Homework Statement

Small Steel balls fall from rest through the opening at A at the steady rate of two per second. Find the vertical separation h of two consecutive balls when the lower one has dropped 3 meters.

Homework Equations

all kinematics equations

The Attempt at a Solution

I found the time it took for 1 ball to reach 3m which was 0.782 seconds, lost from here

 

[Dick]

Ok, so the lower one was dropped 0.728s ago and is 3m down. Then the upper one was dropped half a second earlier. Where is it?

 

[Larrytsai]

so then, i go 0.782/2 is the time for the second ball?

 

[Dick]

so then, i go 0.782/2 is the time for the second ball?

Nooo! 0.782s-(1/2)s. It was dropped 1/2 second earlier. They are falling at a rate of 2/second. Think about it.

 

[Larrytsai]

ohhh that makes sense, thanx