How to calculate theoretical initial velocity?

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Homework Help Overview

The discussion revolves around calculating the theoretical initial velocity required to hit a target 25.6 meters away from a cannon, given specific parameters such as initial velocity, time, and range, while assuming no air resistance.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore the relationship between initial velocity, time, and range, questioning how the initial velocity of 16 m/s was determined. Some express uncertainty about the definitions of range and target distance, while others suggest analyzing horizontal and vertical components of motion.

Discussion Status

Participants are actively engaging with the problem, with some providing insights into the calculations involved. There is a recognition of the need to clarify definitions and assumptions, particularly regarding the initial velocity and its calculation. No explicit consensus has been reached yet.

Contextual Notes

Participants note that the problem involves a simulation where initial velocity was adjusted to achieve the target distance, leading to confusion about the theoretical calculations required. The original instructions emphasize calculating the initial velocity without air resistance.

pill
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I can do with just an equation, but if anyone is willing to help:
Target is 25.6 m away from canon
Initial Velocity = 16 m/s
Time = 2.6 s
Range = 26.7m
No air resistance
 
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pill said:
I can do with just an equation, but if anyone is willing to help:
Target is 25.6 m away from canon
Initial Velocity = 16 m/s
Time = 2.6 s
Range = 26.7m
No air resistance

Is your problem that you have been told the initial velocity is 16 and you don't know how it was calculated?
 
pill said:
I can do with just an equation, but if anyone is willing to help:
Target is 25.6 m away from canon
Initial Velocity = 16 m/s
Time = 2.6 s
Range = 26.7m
No air resistance

Initial Velocity = 16 m/s
:biggrin:

If you mean final then you're going to have to tell me what this Range quantity is
 
genericusrnme said:
Initial Velocity = 16 m/s
:biggrin:

If you mean final then you're going to have to tell me what this Range quantity is

To be honest, I'm not too sure. My instructions state, "Calculate the theoretical initial velocity (no air resistance) required to impact a target with the distance you used in the simulation." I actually messed up when typing the original post: range quantity is the same as target (25.6 m).
 
PeterO said:
Is your problem that you have been told the initial velocity is 16 and you don't know how it was calculated?

For the most part, yes. I used an online simulation for this lab and just continually changed the value of the initial velocity until it hit the target.
 
pill said:
For the most part, yes. I used an online simulation for this lab and just continually changed the value of the initial velocity until it hit the target.

I we look at your original data
Target is 25.6 m away from canon
Initial Velocity = 16 m/s
Time = 2.6 s
Range = 26.7m
No air resistance

and just ignire that initial velocity figure, we know that it covered 25.6 m ( horizintally) in 2.6 seconds - so the horizontal component will be a little less than 10m/s

SInce it took 2.6 seconds to get there, it spent 1.3 seconds gaining height, then 1.3 seconds coming back down.
Standard analysis of vertical motion will tell you how fast it was traveling vertically. Add those two components together using pythagorus and you will get the answer - who knows; it might even be 16 !
 
PeterO said:
I we look at your original data
Target is 25.6 m away from canon
Initial Velocity = 16 m/s
Time = 2.6 s
Range = 26.7m
No air resistance

and just ignire that initial velocity figure, we know that it covered 25.6 m ( horizintally) in 2.6 seconds - so the horizontal component will be a little less than 10m/s

SInce it took 2.6 seconds to get there, it spent 1.3 seconds gaining height, then 1.3 seconds coming back down.
Standard analysis of vertical motion will tell you how fast it was traveling vertically. Add those two components together using pythagorus and you will get the answer - who knows; it might even be 16 !

Thanks! This made is a bit more clear to me. I found got this equation, and your description made it make sense:
Vx=16cos(∡)=26.7m/2.6s
Vy=√(256-(26.7m/2.6s)²)
V=16=√(26.7m/2.6s)²+Vy²
 
Hi, I'm having the same issue and was wondering where you found your final formula? Any help is greatly appreciated!
 

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