Position-time graph/velocity graph help

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Homework Help Overview

The discussion revolves around understanding position-time and velocity-time graphs in the context of free-fall motion. The original poster is new to kinetics and seeks assistance with graphing and interpreting the motion of a falling object, as well as addressing related equations and concepts.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to understand how to graph position and velocity for a free-falling object, questioning whether to start from the top or bottom of the graph. They also inquire about the type of motion represented in the graphs and the meaning of the slope in the velocity-time graph.
  • Some participants suggest using online resources for guidance on graphing, while the original poster expresses confusion about calculating instantaneous velocity and the placement of tangent lines.
  • Further questions arise regarding the representation of acceleration, the calculation of percentage error, and the impact of air resistance on the falling object.
  • The original poster reflects on the relationship between displacement and height, seeking clarification on how to demonstrate this in their work.

Discussion Status

The discussion is ongoing, with the original poster actively seeking feedback on their graphs and calculations. Some guidance has been offered regarding the use of online resources, and participants are engaging with the original poster's questions. There is a recognition of the need for further clarification on several concepts, indicating a productive exploration of the topic.

Contextual Notes

The original poster is working with a test sheet and is navigating the challenges of a new subject area, which includes grappling with multiple concepts and potential errors in their measurements. There is an acknowledgment of the complexity of the questions posed, particularly regarding the effects of air resistance and the interpretation of graphs.

Marleycake
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Homework Statement



Hi, I just started my kinetics course a few days ago and have a few questions about how to graph this and maybe help me out with some of the equations involved, I'm completely new to this and I got this test sheet a few days ago. thanks a lot guys
http://orig11.deviantart.net/afb9/f/2016/080/f/b/help_me_solve_these_people_and_i_ll_give_you_donat_by_marleycake-d9vydtd.png

How do I graph this for the Position-Time Graph and my Velocity-Time Graph

for Position-Time Graph Do I start from the top of the graph (because it represents a free falling object) and make my curve or do I start from the bottom upward ?

Homework Equations


my sheet also says

2. According to your position-time graph what type of motion did the object undergo?. this would be Instantaneous Velocity correct? or maybe I should put Constant Acceleration?

4. construct a V-T graph using your data. Draw the line of best fit. calculate the slope of the line. what doe the slope represent? Wouldn't their be more than one line, also the slope represents avrg velocity correct?
5. If accelerating is supposed to be 9.8 m/s2 [down], determine the percentage error of your value.
% of error ={(measured value ? accepted value)/accepted value] x 100.
could this be due to air resistance acting upon the falling object? also how would i go about calculating air resistance into my equation

6. State possible errors caused in your measured values. what techniques could be used to correct it? maybe incorrect calculations? so a calculator ?
7. Use your V-T graph, and determine the maximum displacement of the object, does this match the height from which the object falls.
I would say yes because if I'm correct my textbook says displacement is a vector and position is a scaler, the only direction the object goes is downward, so they would match? but how would I show that in my work
 
Last edited by a moderator:
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Hello Marleycake, :welcome:

Here at PF we encourage initiative. Such as googling e.g. "position-time graph of a free falling object". Top of the list helps you on your way ! Further help is on the way when you post your first graph.

googling "position-time graph" gets you another useful link in the same site.

PS I like the exercise composers sense of humour. But what a waste of a nice bugatti ! Did they crash the Corvette too, or whas that moving horizontally ?
 
Ok so here are my graphs, is this correct way to graph them based on the picture, am I calculating the instantaneous velocity correcting, is my tangent line not correctly placed, also I've been searching on YouTube (& Google has helped but it kept showing examples of non free fall graphs on how to calculate the instantaneous velocity so I was a bit confused and off putting but I hope I did this correctly also still confused regarding the other questions but will proceed to Google them the best descriptive way I know how
physics__kinetics__position_time_graph__free_fall_by_marleycake-d9vzdyj.jpg


here is the Velocity-Time Graph

velocity_time__graph__of_a_falling_object_at_ff_by_marleycake-d9vzef4.jpg


Also thank you BvU for your encouragement
 
just realized my velocity time graph had to start downward too :( so i'll fix that ..another question is on the y axes should i put m/s/s considering its at a downward freefall? sorry for the billions of questions
 

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