Beginning physics question about solving for time using kinematic equations?

AI Thread Summary
To solve for the height of a racket ball when it leaves the racket, the horizontal distance of 2.15 m and the speed of 5.37 m/s are used to calculate time using the formula time = distance / speed. The user encounters issues when attempting to apply 2-Dimensional kinematic equations, leading to incorrect time calculations. Clarification is sought on whether the final horizontal velocity (Vx) should be considered as 0 or 5.37 m/s. The discussion emphasizes the importance of correctly applying kinematic equations and understanding the components of motion. Accurate interpretation of these equations is crucial for solving the problem effectively.
JohnApplebee
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Homework Statement



A racket ball is struck in such a way that it leaves the racket with a speed of 5.37 m/s in the horizontal direction. When the ball hits the court, it is a horizontal distance of 2.15 m from the racket. Find the height of the racket ball when it left the racket.


Homework Equations



Kinematic equations


The Attempt at a Solution




I already have the solution BUT it's because I solved for time using the formula time = distance / speed. However, I tried solving for time using the 2-Dimensional kinematic equations involving acceleration (-9.8), time, Inital velocity, etc. I plugged in all the variables except for time and my answer for time came out way wrong. So why is that? What am I doing wrong? Thanks.
 
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And just wondering: would final velocity of x (Vx) = 0 or 5.37?
 
JohnApplebee said:
What am I doing wrong?
I don't know. If you show your work maybe I could say.

And just wondering: would final velocity of x (Vx) = 0 or 5.37?
If you were hard-pressed to think about it, which would you say and why?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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