Re: equation of motion problem
- To: mathgroup at smc.vnet.net
- Subject: [mg37627] Re: equation of motion problem
- From: Bill Rowe <listuser at earthlink.net>
- Date: Wed, 6 Nov 2002 06:58:57 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
On 11/5/02 at 5:03 AM, eimers at iastate.edu (Chad Eimers) wrote: >Hello, I need help using Mathematica. I'm trying to solve a standard >equation of motion problem for a decelerating particle. I want to >input a specified height, and find a corresponding initial velocity > >y[t]=-(g+Drag force)*(t^2)/2+v0*t+y0 > >y0 is always equal to 0. > >Can you help? There are a couple of ways to proceed from what you have above. You could re-write the expression above as a Mathematica equation in velocity by taking the derivative of each side getting v == -(g + dragForce)*t + v0 What you would need to do is specify dragForce (note the omitted space) which should probably be specified in terms of v. An alternative would be to set this up as a differential equation, i.e., y'== -(g + dragForce) and use DSolve with inital condition y'(0) = v0. Again, dragForce needs to be specified in a meaningful way.