2D Motion(Baby stuff but i )

  • Thread starter moondawg
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In summary: So it should be:final vertical displacement = initial vertical displacement + (initial y-velocity x time) + (1/2 x acceleration/gravity x time^2)In summary, to determine if the baseball will clear the 3.8m fence 120m away from the home-run, you can use the known initial velocity and angle of the hit to find the time it takes for the ball to reach that distance. Then, using this time, you can plug it into the equation for vertical displacement to see if the ball's height will be greater than 3.8m at that distance. If it is, the ball will clear the fence.
  • #1
moondawg
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QUESTION: A baseball is hit 1.2 meters above the ground, at an angle of 26 degrees, with an initial speed of 80 m/s.
a. Will it clear a 3.8m fence 120m away from the home-run?

MY PROCESS(But not positive I am doing it correctly)
KNOWN
Vx= 80cos26=71.9 m/s
Vy= 80sin26=35.07 m/s
So I did the problem as if from ground level and tried to find time.(using -10 as my acceleration thankyou Mr Werner)
> 0=35.07+-10t t=3.2x2=7s
*got my time to be 7s
Then I am completely lost on what to do after that. I tried finding the how high the ball is when it is insantaneously at 120m in the x direction but my numbers are so extremely wrong... HELLLP MEEEEEE! please
 
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  • #2
Hi moondawg,

moondawg said:
QUESTION: A baseball is hit 1.2 meters above the ground, at an angle of 26 degrees, with an initial speed of 80 m/s.
a. Will it clear a 3.8m fence 120m away from the home-run?

MY PROCESS(But not positive I am doing it correctly)
KNOWN
Vx= 80cos26=71.9 m/s
Vy= 80sin26=35.07 m/s
So I did the problem as if from ground level and tried to find time.(using -10 as my acceleration thankyou Mr Werner)
> 0=35.07+-10t t=3.2x2=7s
*got my time to be 7s

You solved this equation, and then doubled the time to find the time of 7s. But what exactly does this particular time represent? In other words, what is the ball doing (or what can you say about its position) at t=7s?

(Remember that the goal of this problem is to find out if the ball makes is over the fence or not.)

Then I am completely lost on what to do after that. I tried finding the how high the ball is when it is insantaneously at 120m in the x direction but my numbers are so extremely wrong... HELLLP MEEEEEE! please
 
  • #3
Using the final x position(120 meters) and the constant x velocity you found, you can find the time the ball be at that distance. Plug this time into the quation final vertical displacement= initial vertical displacemnt + (initial y-velocity x time) + (acceleration/gravity x time^2). if the answer is less than 3.8 meters, i didn't make it.
 
  • #4
alphysicist said:
Hi moondawg,
You solved this equation, and then doubled the time to find the time of 7s. But what exactly does this particular time represent? In other words, what is the ball doing (or what can you say about its position) at t=7s?

+1

If you can answer this question, you will (most likely) know what's going on. If you understand what is going on, it makes solving the problem a LOT easier.
 
Last edited:
  • #5
Hi jmb88korean,

jmb88korean said:
Using the final x position(120 meters) and the constant x velocity you found, you can find the time the ball be at that distance. Plug this time into the quation final vertical displacement= initial vertical displacemnt + (initial y-velocity x time) + (acceleration/gravity x time^2). if the answer is less than 3.8 meters, i didn't make it.

I believe that quation is missing a factor of 1/2.
 

What is 2D motion?

2D motion refers to the movement of an object in two dimensions, typically represented on a flat plane such as a graph or coordinate system. This means that the object is moving in both the horizontal and vertical directions.

What is the difference between 2D motion and 3D motion?

The main difference between 2D motion and 3D motion is the number of dimensions in which the object is moving. In 2D motion, the object is moving in two dimensions (horizontal and vertical), while in 3D motion, the object is moving in three dimensions (horizontal, vertical, and depth).

What are some examples of 2D motion?

Some examples of 2D motion include a ball rolling down a hill, a car driving on a flat road, a person jumping up and down on a trampoline, and a plane flying in the sky. These objects are all moving in both the horizontal and vertical directions on a 2D plane.

How is 2D motion measured and described?

2D motion is typically measured using a coordinate system, where the x-axis represents the horizontal direction and the y-axis represents the vertical direction. The position, velocity, and acceleration of the object can be described using these coordinates and equations such as distance, speed, and acceleration formulas.

What factors affect 2D motion?

The factors that affect 2D motion include the initial velocity of the object, the force acting on the object, the mass of the object, and the presence of any external forces such as friction or air resistance. These factors can impact the object's speed, direction, and overall motion in the 2D plane.

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