Is My Calculation of 81.48 Meters in Projectile Motion Correct?

AI Thread Summary
The discussion centers on the accuracy of a calculation for projectile motion, specifically questioning the reported height of 81.48 meters. It emphasizes the importance of breaking the problem into segments and suggests that the initial approach may be flawed due to incorrect vertical displacement calculations. The recommendation is made to avoid plugging in numbers too early in the process, advocating for a symbolic approach to maintain clarity and check for errors. Additionally, the need for better organization in presenting the work is highlighted to improve understanding. Overall, the conversation stresses the importance of methodical problem-solving in physics calculations.
Kingyou123
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Homework Statement


Check for first upload

Homework Equations


I wrote them down in my attempt at a solution

The Attempt at a Solution


Second upload, 81.48 meters high seems really wrong to me...
 

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As an aside, looking at your work is hard to follow. I think you could work on your organizational skills and hold off a bit more before plugging in numbers.

Your height at 95 meters downrange is incorrect, why don't we break this problem into segments. What are you trying to find initially to solve this problem?
 
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Since the launch angle is 45 degrees, you can make use of the fact that vx = vy for the components of initial velocity.
 
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The formula you quote at the end of line 6 (d= etc.) is only valid when there is no net vertical displacement.
I heartily endorse Student100's advice to avoid plugging in numbers until the very end. Work the algebra entirely symbolically. Much easier to follow, to check for dimensional consistency, to spot algebraic mistakes...
 
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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 .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
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