Projectile motion figuring out the variables

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Homework Help Overview

The discussion revolves around a projectile motion problem involving a ball thrown on the moon, with known initial velocity and angle. The goal is to determine the maximum height and horizontal distance traveled before the ball strikes the ground.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the use of initial conditions and equations of motion in both x and y components. Questions arise about setting final velocities to zero at the peak of the trajectory and the implications for solving for displacement and time of flight.

Discussion Status

Some participants have provided guidance on writing equations for horizontal and vertical motion, while others are exploring different methods to find time of flight and maximum height. There is an ongoing exchange of ideas about the best approach to take, but no consensus has been reached.

Contextual Notes

Participants are working under the constraints of having limited known variables and are discussing assumptions related to the projectile's motion on the moon, particularly the effect of reduced gravity.

Kaxa2000
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I'm working on a problem that gives me the initial velocity and angle at which the ball is thrown and that it happens on the moon, but that's it. So I only have 2 knowns in the x and y direction. I'm supposed to find how far and how high the ball is thrown before striking the ground. Am I able to set the final velocities equal to zero so I can have 3 of 5 variables? The examples I've looked at haven't done that so I'm confused. Is it possible to solve this?
 
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You've got all you need. The speed, angle and gravity determine the whole flight. Go ahead and write your horizontal and vertical equations and show them here if you would like more help.
 
ok

so

x-component
dx = ?
vx0 = 44.69cos60
vf =
a = 0
t =

y-component
dy = ?
vy0 = 44.69sin60
vf =
a = -g = -1.62m/s^2(on the moon)
t =
 
y-direction
V = Vi + at AND d = Vi*t + .5*a*t^2
V = 44.69*sin(60) - 1.62*t AND y = 44.69*sin(60)*t - .81*t^2

I guess the next step is to get the time of flight, or half of it. There are several ways to do this. Some recall the vertical velocity at half time, others like to use the known velocity at the full time of flight. Or you could use the fact that y = 0 at the end of the flight.
 
So I would set vf for the y component equal to 0 m/s since at it's highest point the velocity is zero?? Then solve the y component for the displacement to get the distance it is at when it reaches its highest point? Then I could also solve for the time and then multiply it by 2 since at the highest point it's only halfway between the horizontal displacement and then solve for the horizontal displacement.

I need to find the highest point and how far it would travel before striking the ground.

Let me know if this is right..thanks for any help
 
All right! You've got it all planned.
 
Okay...thanks!
 

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