Minimum Speed for a Horizontally Projected Diver to Clear a Ledge

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Homework Help Overview

The problem involves a swimmer diving off a cliff with a horizontal leap, needing to determine the minimum speed required to clear a ledge below. The context is projectile motion, specifically focusing on the effects of gravity and the relationship between speed, distance, and time.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relevance of the swimmer's weight in the context of projectile motion and question why it was included in the problem statement. There is an exploration of whether the weight serves to test understanding of gravitational independence from mass.

Discussion Status

The discussion is active, with participants engaging in questioning the necessity of the diver's weight in the calculations. Some express confusion about the problem's requirements, while others provide insights into the nature of projectile motion and its principles.

Contextual Notes

Participants note that the problem is presented as a standalone question without additional context or parts, leading to discussions about the potential intent behind the inclusion of the diver's weight.

dregozo

Homework Statement


A daring 510N swimmer dives off a cliff with a horizontal leap. What must his minimum speed be just as he leaves the top of the cliff so that he will miss the ledge at the bottom, which is 1.75m wide and 9.00m below the top of the cliff?

Homework Equations


s=1/2gt^2 ; v=s/t

The Attempt at a Solution


I used the above equations in that order, and arrived at an answer. My issue is that I did not use the 510N at all! Where does the diver's weight come in?
 
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dregozo said:
Where does the diver's weight come in?
It doesn't! This is a projectile motion problem and all projectiles have the same acceleration, independent of mass.
 
My exact reasoning.. so why did the examiner include the 510N?? To test students if they know that g is independent of mass?
 
dregozo said:
so why did the examiner include the 510N?? To test students if they know that g is independent of mass?
Sure, why not? That's one good reason to include it -- to see how confident you are with the basics.

Is this just a part of a multi-part question?
 
No, it's the entire question. Nothing more was asked. Strange, right?
 
It happens often. Keeps you on your toes! (And drives students nuts!) :smile:
 
I wish I weighed 510N :-(
 
CWatters said:
I wish I weighed 510N :-(
LOL. (Me too!)
 

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