Solving Free Falling Objects Problem

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The problem involves a girl throwing keys upward to a friend located 3.90 meters above, with the keys being caught after 1.30 seconds. To find the initial velocity of the keys, the kinematic equation x = x_0 + v_0 t + (1/2) a t^2 is suggested. Attempts to solve for the initial velocity and final velocity using basic kinematic principles yielded incorrect results. The discussion emphasizes the importance of correctly applying kinematic equations to determine the velocities involved. Understanding the motion of free-falling objects is crucial for solving such problems effectively.
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Homework Statement


A girl throws her set of keys to her friend upward who is in a window 3.90m above. the keys are caught later at 1.30s by the friends hand.


Homework Equations


a. With what initial velocity were the keys thrown?
b. What was the velocity of the keys just before they were caught?

The Attempt at a Solution


a. i tried finding change in x/change in t but got the wrong answer
b. i tried using a kinematic equation and solving for Vfinal but got the wrong answer...
 
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steph35 said:

Homework Statement


A girl throws her set of keys to her friend upward who is in a window 3.90m above. the keys are caught later at 1.30s by the friends hand.


Homework Equations


a. With what initial velocity were the keys thrown?
b. What was the velocity of the keys just before they were caught?

The Attempt at a Solution


a. i tried finding change in x/change in t but got the wrong answer
b. i tried using a kinematic equation and solving for Vfinal but got the wrong answer...

Consider using the equation:

x = x_0 + v_0 t + (1/2) a t^2
 

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