- #1

kraigandrews

- 108

- 0

## Homework Statement

A particle falls in Earth's gravity. The force of air resistance is F = −αv

**v**where v is the velocity, v is the speed, and α is a constant. (The direction of the force is opposite to the velocity, and the magnitude of the force is αv^2.) If the terminal speed is 20.2 m/s and the mass is 2.6 kg, determine the constant α.

## Homework Equations

F=mdv/dt

## The Attempt at a Solution

m(dv/dt)=mg-aplhav

thus v(t)=(mg/aplha)(1-e^(-(alpha/m)t))

so aplha if I am correct should be (mg/Vterminal)=1.263, however I am not sure of the units for this. My guess would be kg/s however my homework programs says that is incorrect, and also I feel I may have neglected the [/B]v[/B] and the magnitude of the opposing force causing a wrong answer.

If someone could shed some light on this it is greatly appreciated.