You drop a ball from a window on an upper floor of a building. it strikes the ground with velocity v. You now repeat the drop, but have a friend down on the street who throws another ball upward at velocity v. Your friend throws the ball upward at exactly the same time that you drop yours from the window. At some location, the balls pass each other. Is this location at the halfway point between window and ground, above this point, or below this point?

Question

anonymous · Answer

I know that initial velocity from top is 0 initial time is 0 and acceleration from top is positive g

anonymous · Answer

i know that from bottom initial velocity is v acceleration is negative g initial time is 0

anonymous · Answer

They cross at time T

anonymous · Answer

below, due to the fact that when the ball is going down is it accelerating and when it is going up it is deaccelerating because of gravity

anonymous · Answer

hamish I dont think youre correct, because the ball at the bottom starts with greater velocity, whereas the ball at top starts from 0 velocity

anonymous · Answer

I think hamish93 is right but it would also depend upon the force with which the friend from below threw the ball.

anonymous · Answer

if  " v " is a constant the ball from the person below would'nt  go  verry  far at  all ... given that  the " V " from the first  ball was due to  an  act  of gravity  ...the velosity  for the second ball  must  be greater for the balls to meet  in the at  all  (  the  huge diffrence being dropped , thrown )

anonymous · Answer

it says it was thrown at v. the velocity of the ball right before it hits the ground. I just need to prove this mathematically. I know its above half way

anonymous · Answer

the way  i  read the question ... " V " is being used as a constant ... whitch  can not be for the balls to  meet  in  air example (  ball dropped  " V "  will  increse over distance  ,  given  the  mass of the ball and the down force of gravitys pull  ) 

( ball thrown  up  " V " will decrese decreses givin the balls mass , the down force of of gravitys pull ) 

so .. for the balls to  meet  in  air the " V "  can not be the same for bolth balls ....you  must  add F (  force )  behind the thrown  ball to  acchive a  greater "  V "  of the 2nd ball  for bolth balls to  meet  in  air