- #1
Gbox
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Homework Statement
A particle is moving in a liquid ##a=-kv## when ##k## is a constant, if a constant force is being apply on the particle ##a=-kv+\frac{F}{m}##.
1. for the formula that's include the force, find the diferencial function where ##v## will appear in it explicitly, ad its derivites
2. define a new variable ##U=v-\frac{F}{mk}## and substitute in place of ##v## that is in the diferencial function.
3. guess a solution in the form of ##U=AE^{-Bt}## where A and B are contestants, find B that for it the equation is true
4. find A and when the velocity at ##t=0## is 0
5.find ##x(t)## when ##x(t=0)=0##
6. according to the result on 4, what will be the velocity of the particle when ##t\rightarrow \infty##
Homework Equations
##a=-kv##
##x+x_o+v_0t+\frac{at^2}{2}##
The Attempt at a Solution
1. I should be looking for the functions which its derivites is ##a=-kv+\frac{F}{m}## so ##v=-kvt+ frac{Ft}{m}##
And ##x=x_0+\frac{kvt^2}{2}+\frac{Ft^2}{2m}##?
2.##x=x_0+\frac{k*(v-\frac{F}{mk})*t^2}{2}+\frac{Ft^2}{2m}##
Are 1 and 2 are correct?