How fast is a falling object going without riction

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Homework Help Overview

The problem involves calculating the final velocity of an object falling from rest over a distance of 25 meters, assuming no air friction. The subject area is kinematics, specifically the motion of falling objects under the influence of gravity.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply a formula to calculate velocity but questions the validity of their result. Some participants point out errors in unit conversion and suggest using kinematic equations. Others inquire about the possibility of using the square root of a derived value.

Discussion Status

The discussion is ongoing, with participants providing hints and corrections regarding the application of formulas. There is no explicit consensus on the correct approach yet, but guidance has been offered regarding the need for a proper formula relating initial and final velocities.

Contextual Notes

Participants are navigating the constraints of the problem, including the assumption of no air friction and the need for accurate application of kinematic principles. There is also a mention of a dimensionless factor that may be relevant to the calculations.

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An object falls from rest for a distance of 25 m. If there was no air friction, how fast was it going at that distance?

I'm not sure but I would imagine v=(25m)(9.8m/s^2)= 245m/s ? which seems quite high to me so I know I am not calculating it correctly.
 
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You sure aren't. The units of your v are m^2/sec^2. That's not a velocity. It's a velocity squared. Hint, hint. There's a shortcut formula you can use, or you can just do straight kinematics. Like x=x0+v0*t+(1/2)*a*t^2.
 
so should I just take the square root of 245 then?
 
Nope. There's another dimensionless factor you are missing. If you are going to go for a shortcut, I think you should find the correct formula, there is one that relates initial velocity, final velocity and distance traversed.
 

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