You are not logged in.
A parachutist of mass m, falling vertically with mass m , speed U at height h above ground, he experiences a resistance equal to
show that the velocity at time t isso this is what i've done so far
from newtons 2nd i get:
taking the dot product i with the z components we get
dividing by m
let
then we get:the integrating factor is
so
So i get the general solution
Now its obvious this is not the required solution if anyone can please help me to get the complete solution i will be very gratefull
Offline
I got this
the net accel = gravity - resistance
And after you solve the general form of z
you have to put when z=h, dz/dt=U, to get the specific form
Last edited by Dragonshade (2008-04-25 03:40:48)
Offline
hey i put the extra negative sign in there because its in the negative Z direction so we have the vector -K
I've tried to find the second part of the equation
however i realized the dz/dt is equal to velocity not speed so i'm still not sure how to get the
Last edited by ROBBYM (2008-04-28 06:33:11)
Offline
I dont think the resistant is to the same direction as the gravity. thereforce they must be of different sign regardless of the observer
Offline