- #1
Mirole
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Homework Statement
You have taken a summer job at a warehouse and have designed a method to help get heavy packages up a 15º ramp. In your system a package is attached to a rope which runs parallel to the ramp and over a pulley at the top of the ramp. After passing over the pulley the other end of the rope is attached to a counterweight which hangs straight down. In your design the mass of the counterweight is always adjusted to be twice the mass of the package. Your boss is worried about this pulley system. In particular, she is concerned that the package will be too difficult to handle at the top of the ramp and tells you to calculate its acceleration. To determine the influence of friction between the ramp and the package you run some tests. You find that you can push a 50 kg package with a horizontal force of 250 Newtons at a constant speed along a level floor made of the same material as the ramp.
Homework Equations
Fnet=ma
The Attempt at a Solution
Block 1:
(Fnet)y = n + T - Fgcos[tex]\theta[/tex]= 0
(Fnet)y = n = mgcos[tex]\theta[/tex]
(Fnet)x = n + T - Fgsin[tex]\theta[/tex] - fk = ma
(Fnet)x = T - Fgsin[tex]\theta[/tex] - fk = ma
(Fnet)x = 980 - Fgsin[tex]\theta[/tex] - mu_k(mgcos[tex]\theta[/tex]) = ma
(Fnet)x = 980 - gsinmgcos[tex]\theta[/tex] - (mu_k)cos[tex]\theta[/tex] = a
Block 2:
(Fnet)x = 0
(Fnet)y = T - 2mg = 0
(Fnet)y = T = 2*mg
(Fnet)y = T = 2*50*9.8, so T= 980N
I'm confused as to what to do next, because I don't think I'm doing this right and I don't have the co-efficient of kinetic friction.