Welcome
Username or Email:

Password:


Missing Code




[ ]
[ ]
Online
  • Guests: 38
  • Members: 0
  • Newest Member: omjtest
  • Most ever online: 396
    Guests: 396, Members: 0 on 12 Jan : 12:51
Members Birthdays:
One birthday today, congrats!
gentoo_daemon (42)


Next birthdays
04/20 gentoo_daemon (42)
04/21 kilovolt (49)
04/21 wannabegeekTC (49)
Contact
If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.


Special Thanks To:
  • Aaron Holmes
  • Aaron Wheeler
  • Adam Horden
  • Alan Scrimgeour
  • Andre
  • Andrew Haynes
  • Anonymous000
  • asabase
  • Austin Weil
  • barney
  • Barry
  • Bert Hickman
  • Bill Kukowski
  • Blitzorn
  • Brandon Paradelas
  • Bruce Bowling
  • BubeeMike
  • Byong Park
  • Cesiumsponge
  • Chris F.
  • Chris Hooper
  • Corey Worthington
  • Derek Woodroffe
  • Dalus
  • Dan Strother
  • Daniel Davis
  • Daniel Uhrenholt
  • datasheetarchive
  • Dave Billington
  • Dave Marshall
  • David F.
  • Dennis Rogers
  • drelectrix
  • Dr. John Gudenas
  • Dr. Spark
  • E.TexasTesla
  • eastvoltresearch
  • Eirik Taylor
  • Erik Dyakov
  • Erlend^SE
  • Finn Hammer
  • Firebug24k
  • GalliumMan
  • Gary Peterson
  • George Slade
  • GhostNull
  • Gordon Mcknight
  • Graham Armitage
  • Grant
  • GreySoul
  • Henry H
  • IamSmooth
  • In memory of Leo Powning
  • Jacob Cash
  • James Howells
  • James Pawson
  • Jeff Greenfield
  • Jeff Thomas
  • Jesse Frost
  • Jim Mitchell
  • jlr134
  • Joe Mastroianni
  • John Forcina
  • John Oberg
  • John Willcutt
  • Jon Newcomb
  • klugesmith
  • Leslie Wright
  • Lutz Hoffman
  • Mads Barnkob
  • Martin King
  • Mats Karlsson
  • Matt Gibson
  • Matthew Guidry
  • mbd
  • Michael D'Angelo
  • Mikkel
  • mileswaldron
  • mister_rf
  • Neil Foster
  • Nick de Smith
  • Nick Soroka
  • nicklenorp
  • Nik
  • Norman Stanley
  • Patrick Coleman
  • Paul Brodie
  • Paul Jordan
  • Paul Montgomery
  • Ped
  • Peter Krogen
  • Peter Terren
  • PhilGood
  • Richard Feldman
  • Robert Bush
  • Royce Bailey
  • Scott Fusare
  • Scott Newman
  • smiffy
  • Stella
  • Steven Busic
  • Steve Conner
  • Steve Jones
  • Steve Ward
  • Sulaiman
  • Thomas Coyle
  • Thomas A. Wallace
  • Thomas W
  • Timo
  • Torch
  • Ulf Jonsson
  • vasil
  • Vaxian
  • vladi mazzilli
  • wastehl
  • Weston
  • William Kim
  • William N.
  • William Stehl
  • Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Forums
4hv.org :: Forums :: General Science and Electronics
« Previous topic | Next topic »   

Math and Physics of Upward Acceleration.

Move Thread LAN_403
Patrick
Sat Jul 08 2017, 08:24PM
Patrick Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Im having a difficult time with what should be a simple problem. My brain is just to sore to deal with 1D kinematics.
So, coming here to the 4hv.org forum where other smart people are, i decided to simplify the problem.

Now, in a simplified problem:
Throwing a 750g ball straight up with 25 N-sec of force with the force applied in 1.6 seconds. how high will it go ? (ignore aerodynamics)

Im trying to think in terms of the v(t), x(t), a(t) graphs.



Back to top
hen918
Sat Jul 08 2017, 09:53PM
hen918 Registered Member #11591 Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556
N-sec isn't force. N, newtons, that's force.
assuming your units were right:
25/1.6 = the force in newtons = 15.625 N
force = mass * acceleration, therefore force / mass = acceleration
15.625/0.75 = 20.833 m/s^2
multiplying by the time it took to accelerate, we find the ball reached the following speed at the end of the throw:
20.833*1.6 = 33.33 m/s
The easiest way to proceed is to find the energy in the ball: K.E. = 0.5mv^2
0.5*0.75*33.33^2 = 416.67 J
now we also know that potential energy is equal to height multiplied by mass and g so assuming that nothing is lost: energy / (mass*g) = height:
height = 416.67/(0.75*9.812) = 56.6 m

I'm sorry if this explanation isn't very general, and makes use of the energy shortcut.
Back to top
Patrick
Sat Jul 08 2017, 11:24PM
Patrick Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
hen918 wrote ...

I'm sorry if this explanation isn't very general, and makes use of the energy shortcut.

This is getting me where i need to be.
Back to top
2Spoons
Sun Jul 09 2017, 09:37PM
2Spoons Registered Member #2939 Joined: Fri Jun 25 2010, 04:25AM
Location:
Posts: 615
You need to include gravity in the force eqn. 750g exerts a downward force of ~7.35 N. So the nett accelerating force is only 8.275 N.
Back to top

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob

Go to:

Powered by e107 Forum System
 
Legal Information
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.