- #1
rysezhae
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Homework Statement
I need to find the initial acceleration of a steel object that weighs .89 kg, that is pulled along a steel a rail by a cord. The cord is at an 45 degree angle and has a tension of 21 N. The friction coefficents(spelled right?) of steel on steel are: .8 for static friction, .6 for kinetic friction and .002 for for rolling friction.
Homework Equations
F=ma
Fp=21 N
The Attempt at a Solution
What i did was separate the net forces into the x direction and the y direction. In the x direction i got Fpcos(theta)-Fk=max (x = x direction). I then solved for ax giving me (Fpcos(theta)-Fk)/m.
Since Fk =ukFn (kinetic friction coefficent * normal force), i substituted that in for Fk in ax. In the y direction i got, Fpsin(theta)+Fn-Fe=0. I solved for Fn then substituted that back in for Fn in the ax equation getting: (Fpcos(theta)-uk(Fe-Fpsin(theta)))/m. No sig figs required, since the problem doesn't say anything about it