Projectile Motion — How far from the gun does the bullet land?

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Homework Help Overview

The discussion revolves around a projectile motion problem involving a bullet fired from a gun, focusing on the relationship between the horizontal and vertical components of motion. Participants are exploring how to determine the distance the bullet travels horizontally before hitting the ground, given its initial velocity components and the acceleration due to gravity.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants express uncertainty about how to connect the x-component and y-component of velocity. Some suggest treating the horizontal and vertical motions as independent, while others question the meaning of "linking" these components. There are discussions about relevant equations and methods to find the time of flight and horizontal distance.

Discussion Status

The discussion is ongoing, with participants sharing their interpretations and hints regarding the problem. Some guidance has been offered about considering the independence of the motions, but there is no clear consensus on the approach to take.

Contextual Notes

Participants are working under the assumption that there is no air resistance affecting the bullet's flight, and they are trying to clarify the implications of this assumption on the calculations involved.

Tinkylo
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Homework Statement
The bullet fired from a gun on the ground has a velocity v. The x-component of the velocity is 8.4 ms-1 and the y-component of the velocity is 9.2 ms-1. x is the horizontal axis and y is the vertical axis. What is the distance in m between the gun and the point where the bullet hits the ground? Acceleration due to gravity is 9.8ms-2. Assuming there is no air resistance during the bullet's flight.
Relevant Equations
Not sure
I don't know how to link the x-component and y-component together.
 

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Tinkylo said:
I don't know how to link the x-component and y-component together.
Distance, start velocity, final velocity, time, acceleration. For which does the same value apply to both coordinates?
 
Tinkylo said:
I don't know how to link the x-component and y-component together.
As there is no air resistance, the vertical and horizontal components of velocity are not linked in the problem.Consider the problem as independent horizontal and vertical motions.
 
Tinkylo said:
Relevant Equations:: Not sure

I don't know how to link the x-component and y-component together.
Don't link those, they are giving you the vertical and horizontal components of the initial velocity in order to facilitate the problem.
Hits:
Purely vertical movement: decelerated while moving up / stop / accelerated while falling down.
Purely horizontal movement: non-accelerated and lasting as much as the up-down vertical movement.
 
Lnewqban said:
Don't link those
It's not clear what @Tinkylo means by linking them. My interpretation is finding something that links the horizontal and vertical equations. See my hint in post #2.
 
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Tinkylo said:
Homework Statement:: The bullet fired from a gun on the ground has a velocity v. The x-component of the velocity is 8.4 ms-1 and the y-component of the velocity is 9.2 ms-1. x is the horizontal axis and y is the vertical axis. What is the distance in m between the gun and the point where the bullet hits the ground? Acceleration due to gravity is 9.8ms-2. Assuming there is no air resistance during the bullet's flight.
Relevant Equations:: Not sure

I don't know how to link the x-component and y-component together.
You can work it out from first principles from the equations for x and y as a function of t (time). This involves finding the value of t when y = 0 and then using that value of t in the equation for x. Or you can use the relationship between range, velocity and launch angle that you may have been given: ##R = \frac{v_0^2 \sin{2\theta}}{g}##. If you use this relationship, you will have to find ##v_0## and the launch angle. Which method do you wish to use?

AM
 

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