Discover the Meaning of Δy in Projectile Motion Formula: A Comprehensive Guide

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SUMMARY

The discussion clarifies the meaning of the formula Δy = [(sin(2θ)(Vi)]^2 / 2a in the context of projectile motion. Participants confirm that this formula represents the maximum height attained by a projectile when launched at an angle θ with an initial velocity Vi, under the influence of gravity (a = 9.8 m/s²). A correction is proposed to replace sin(2θ) with sin(θ) for accurate calculations. The conversation emphasizes the importance of understanding the vertical component of velocity in projectile motion equations.

PREREQUISITES
  • Understanding of projectile motion principles
  • Familiarity with trigonometric functions, specifically sine
  • Knowledge of kinematic equations in physics
  • Basic understanding of gravitational acceleration (9.8 m/s²)
NEXT STEPS
  • Study the derivation of the maximum height formula in projectile motion
  • Learn about the components of projectile motion and their calculations
  • Explore the effects of varying launch angles on projectile trajectories
  • Investigate the role of air resistance in real-world projectile motion
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Students of physics, educators teaching projectile motion concepts, and anyone interested in understanding the mathematics behind the trajectories of projectiles.

staka
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I would like to simply know what Δy=[(sin2θ)(Vi)]^2/2a represents..
The formula only requires the angle and the initial velocity (along with the usual a=9.8m/s^2), so what height does the equation represent?
 
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The distance a projectile travels (over flat ground) is [sin(2θ)*(v^2)]/a, very similar to what you have there. Is there a chace you misread it?
 
well that's the distance..
I think I got it now though, it's possibly the maximum height over a flat ground.
 
Oh yeah you're correct, i just googled it a bit and it came up. It is the maximum height you reach
 
staka said:
I would like to simply know what Δy=[(sin2θ)(Vi)]^2/2a represents..
The formula only requires the angle and the initial velocity (along with the usual a=9.8m/s^2), so what height does the equation represent?
That's almost the formula for the maximum height of a trajectory. To correct it, replace sin2θ with sinθ.
 
So one of the famous equations for the motion of a projectile is as follows:

v2=u2+2as

v = final velocity
u = initial velocity
a = g = -9.8m/s2
s = distance travelled

Now, for a projectile being fired at an angle, the vertical component of velocity is usin%, where % is the angle between the ground and the direction of projection.

Rearrange your equation, with v=0 to get the maximum height attained by a projectile (note that in your equation, your v is my u).

You get:

s = u2/-2a = (usin%)2/-2a

As a = -9.8, you can ignore the minus sign and you basically have your equation (except for the sin2% bit).

Yes I don't know how to make greek alphabet symbols, so a % for an angle will do :D

Hope that helps.
 

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