Simple question about projectile motion

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Discussion Overview

The discussion revolves around the principles of projectile motion, specifically regarding the selection of initial angles and velocities to hit a target at a specified range of 8 miles. The context includes considerations of ideal conditions, such as neglecting air resistance and Earth's curvature.

Discussion Character

  • Exploratory, Technical explanation, Homework-related

Main Points Raised

  • One participant suggests that there are infinite combinations of initial velocities and angles that can achieve a given range, specifically mentioning an initial angle of pi/4 as the most efficient.
  • Another participant acknowledges that while any angle can theoretically be valid, they emphasize that the path and final velocity will differ with each angle chosen.
  • It is noted that the discussion assumes ideal conditions by neglecting air resistance and the curvature of the Earth.
  • A participant reiterates that pi/4 is the most efficient angle for achieving the target range under the specified conditions.

Areas of Agreement / Disagreement

Participants generally agree that pi/4 is the most efficient angle for projectile motion in this context, but there is acknowledgment that other angles can also achieve the target range, leading to a nuanced discussion without a definitive consensus on the implications of different angles.

Contextual Notes

The discussion is limited by the assumptions of neglecting air resistance and Earth's curvature, which may affect the applicability of the claims made regarding angle selection and efficiency.

Saladsamurai
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I recently helped someone in the homework forum with a problem that asked him to hit a target 8 miles away using a cannon or some other device involving projectile motion. Essentially, all we had to do was choose an initial angle and an initial velocity that would correspond to said angle that would reach a certain range R=8miles. Now my question is: we choose pi/4 as the initial angle because it is the most efficient; are there an infinite amount of combinations of initial velocities and angles that will reach a given range R ?
 
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I guess you could say that but the path and final velocity would be different for each angle. The problems I have always dealt with specify how to pick the angle, but if we are neglecting air drag and the curvature of the Earth then 45 degrees would be probably be the best angle to chose.
 
In this specific example we were neglecting air resistance and curvature.
 
You are right though that any angle is valid. Though pi/4 is the most efficient choice.
 

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