Projectile race track physics help

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Homework Help Overview

The problem involves a projectile motion scenario where a rider jumps off a slope at a specific angle and height. The discussion centers around determining the speed at which the rider leaves the slope, the horizontal distance traveled, and the maximum height attained during the jump.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the interpretation of the time the rider is airborne and its implications for calculating speed. There are questions about how to determine the initial speed off the slope and the relevance of the jump's height in the calculations.

Discussion Status

Some participants have provided insights into the relationship between time and height in projectile motion, suggesting that the initial velocity must be considered in the vertical direction. There is an ongoing exploration of how to apply the equations of motion to this specific scenario.

Contextual Notes

Participants are navigating the complexities of the problem, particularly the differences in height from which the jump starts and ends, which affects the calculations. The original poster has provided some equations but has not yet resolved the problem.

Sam Fred
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Homework Statement


The Track for this racing event was designed so that riders jump off the slope at 30°, from a
height of 1m. During a race it was observed that the rider shown in Fig. 2 remained in mid air for
1s. Determine,
1) the speed at which he was traveling off the slope, ( 2points)
2) the horizontal distance he travels before striking the ground, (2points)
3) the maximum height above the ground he attains (3points)

Homework Equations


v=vi + at
y=yi + vi t + 0.5 a t^2

The Attempt at a Solution


in the attachment .
 

Attachments

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hey man, welcome to physicsforums! When they say he remained in mid-air for 1 second, I think this means that he was airborne (not touching ground) for 1 second. Not that he was half-way through his jump at 1 second.
 


aha ... thanks man ... but how would i know the speed off he slope ?
Do i repeat the same steps with substituting t = 0.5 sec
 


No. That would work if his jump started and finished at the same height. But in this problem, it doesn't, because he starts the jump at 1m height, and finishes the jump at zero metres. So at t=0.5 sec, he is not at the highest part of the jump (he has already gone past that point). So the time when he has zero velocity will be some value, which is greater than 0.5 seconds.

You can use this equation you wrote: y=yi + vi t + 0.5 a t^2 (also, remember that vi needs to be the vertical component of initial velocity). You know the total change in height and you know the change in time, so you can simply solve for vi
 

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