Projectile motion (ground to ground)

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Homework Help Overview

The discussion revolves around a projectile motion problem involving a baseball hit at a height of 1.30 m and caught at the same height after traveling a horizontal distance alongside a wall. Participants are tasked with determining the horizontal distance traveled, the magnitude and angle of the ball's velocity after being hit, and the height of the wall.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply kinematic equations and considers the relationship between the vertical and horizontal components of velocity. Some participants suggest analyzing the horizontal velocity while the ball is above the wall and calculating average velocity based on distance and time.

Discussion Status

Participants are exploring various aspects of the problem, including the relationship between average and instantaneous velocity. Guidance on using LaTeX for unit vectors has been provided, indicating a collaborative effort to clarify notation and mathematical expressions.

Contextual Notes

There is mention of known values such as gravitational acceleration and initial vertical velocity, but the discussion reflects uncertainty about the next steps in solving the problem. The original poster expresses being stuck, indicating potential gaps in understanding or application of concepts.

J-dizzal
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Homework Statement


In the figure, a baseball is hit at a height h = 1.30 m and then caught at the same height. It travels alongside a wall, moving up past the top of the wall 1.1 s after it is hit and then down past the top of the wall 3.9 s later, at distance D = 42 m farther along the wall. (a) What horizontal distance is traveled by the ball from hit to catch? What are the (b) magnitude and (c) angle (relative to the horizontal) of the ball's velocity just after being hit? (d) How high is the wall?
http://edugen.wileyplus.com/edugen/...u/ch0/EAT_13496164302600_3698173899564502.GIF

Homework Equations


I have the kinematic equations and equations for motion (while in flight)

The Attempt at a Solution


known solns:
ay = -g = -9.8m/s2
v0y = 29.89 m/s
vfy = -29.89 m/s
Δy = 0
t= 6.1s

im stuck at this point. i think maybe i can set the v at max height equal to the x component of v0?[/B]
 
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Consider its horizontal velocity for the time it is above the wall.
 
haruspex said:
Consider its horizontal velocity for the time it is above the wall.
velocity for the time the ball is over the wall,
v = Δd/Δt
= 42m / 3.9
= 10.77m/s.
But this is average velocity, if ax is constant and vx is constant then the avg velocity is equal to v at any point?

Then,
vavg = v0x = v0cosθi,
is the x component of v0.

Thanks.
How do you type unit vecotors i,j, and k with hats?
 
J-dizzal said:
velocity for the time the ball is over the wall,
v = Δd/Δt
= 42m / 3.9
= 10.77m/s.
But this is average velocity, if ax is constant and vx is constant then the avg velocity is equal to v at any point?

Then,
vavg = v0x = v0cosθi,
is the x component of v0.

Thanks.
How do you type unit vecotors i,j, and k with hats?
Yes.
For the hat, use Latex. Putting a consecutive pairs of hash symbols(#) starts and ends a Latex string. Using dollar symbols instead puts the Latex on a line of its own. A hat over a character is achieved by writing \hat in front of it. Put a space after hat. If it is to go over something more complicated than a single character, use curly brackets: \hat{x^2} will produce ##\hat{x^2}##.
You can see how others have written latex by right-clicking on the generated text in their post and selecting View math as. You can then cut and paste to produce your own.
Sometimes the Latex refuses to work properly even though what you've written looks right. It's usually because you've included an unusual ASCII character or have some font change within it. Latex is jealous - in the Latex string, all must be Latex.
Always use the Preview button to check the Latex before posting.
 

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