Calculating Distance and Time for Freely Falling Bodies

AI Thread Summary
A ball is dropped from a 24 m high cliff while a second ball is thrown upwards with an initial speed equal to the first ball's impact speed. The first ball takes 2.21 seconds to hit the ground, reaching a final velocity of 21.7 m/s. To find where the two balls cross paths, expressions for their positions as functions of time must be established. The distances traveled by each ball can be added and equated to the height of the cliff for solving the intersection point. Clarification on the equations and calculations is needed for further assistance.
Chiralic
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Homework Statement



A ball is dropped from rest from the top of a cliff that is 24 m high. From ground level a second ball is thrown straight up at the same instand theat the first ball is fropped. The initial speed of the second ball is the same as that with which the fist ball hits the ground. In absense of air resistance, the motions of the balls are just the revers of each other. How far below the cliff do the balls cross paths?

Homework Equations

kinematic equations involving vi, vf, a, x and y and time.



The Attempt at a Solution


I know it takes 2.21 s to fall 24 m, and for ball 2 to reach vi of ball one. Vf1 = vi2= 21.7 m/s

help!
 
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So far, so good. Now write expressions for the position of each ball as a function of time. (Make sure you measure the position from the same point for each.) Then you can solve for where the paths intersect.
 
Sorry, you've completely lost me...I keep getting 24 m with what I'm trying...any other thoughts?
 
Chiralic said:
Sorry, you've completely lost me...I keep getting 24 m with what I'm trying...any other thoughts?
Can you show what you're doing?
 
write the distances traveled by each as a function of time
then add them and equate to the hight of the cliff

does this help? or do u need more?
 
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