- #1
Clever_name
- 125
- 0
Homework Statement
see this link http://i45.tinypic.com/10gwhw2.jpg
Homework Equations
F=kx, F=ma
The Attempt at a Solution
ok first I find the total length of the pulley system,
2Sa+Sb=L, differentiating with respect to time i get,
2Va + VB=0 and thus 2Aa+Ab =0
So Aa =-Ab/2
next I first analyze block A and do a force balance to get,
-Ma*g - k*x + 2T = Ma*Aa
following this i analyze Block B doing a force balance again,
T-Mb*g = Mb*Ab
so to eliminate one of the variables I input Aa=-Ab/2 into the equation describing block A.
I get -Ma*g-k*x+2T+Ma(-Ab/2)
then i get -2(Ma*g-k*X+2T)=Ab
so now i substitute this in Block B with real values
T-98.1=10(19.62-400+2T)
so T = 195.04
then Ab = 19.62-400+2(195.04) = 9.7 m/s^2
So now I have (delta)y = 0.5 m A=9.7
using the following equation i can solve for t, Δy=(1/2)at^(2)
doing so i get 0.32s
thus v = at = 9.7(0.32) =3.104 m/s
However i do not have a solution for this exercise and unsure if my attempt is correct or not. Any help is greatly appreciated thanks!