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VinnyCee
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The 30 lb box A is released from rest and slides down along the smooth ramp and onto the surface. Determine the distance s from the end of the surface to where the box stops. The coefficient of kinetic friction between the cart and the box is [itex]\mu_k\,=\,0.6[/itex].
http://img224.imageshack.us/img224/8509/problem14343jq.jpg
Here is what I have so far:
[tex]-W\,\Delta\,y\,=\,(-30\,lb)\,(-4\,ft)\,=\,120\,ft\,lb[/tex]
[tex]\sum\,F_y\,=\,N\,-\,W\,=\,0\,\Rightarrow\,N\,=\,W\,=\,30\,lb[/tex]
[tex]\sum\,F_x\,=\,-f_k\,=\,m\,a_x\,\Rightarrow\,-\mu_k\,N\,=\,m\,a_x[/tex]
[tex](-0.6)\,(30\,lb)\,=\,(0.932)\,a_x[/tex]
[tex]a_x\,=\,\frac{-18.6}{0.932}\,=\,-19.3\,\frac{ft}{s^2}[/tex]
Now what?
I know I need to find [itex]v_f[/itex] and the bottom of the hill and I am probably supposed to use a work-energy equation?
[tex]\sum\,T_1\,+\,\sum\,U_{1\,-\,2}\,=\,\sum\,T_2[/tex]
Please help, thanks.
http://img224.imageshack.us/img224/8509/problem14343jq.jpg
Here is what I have so far:
[tex]-W\,\Delta\,y\,=\,(-30\,lb)\,(-4\,ft)\,=\,120\,ft\,lb[/tex]
[tex]\sum\,F_y\,=\,N\,-\,W\,=\,0\,\Rightarrow\,N\,=\,W\,=\,30\,lb[/tex]
[tex]\sum\,F_x\,=\,-f_k\,=\,m\,a_x\,\Rightarrow\,-\mu_k\,N\,=\,m\,a_x[/tex]
[tex](-0.6)\,(30\,lb)\,=\,(0.932)\,a_x[/tex]
[tex]a_x\,=\,\frac{-18.6}{0.932}\,=\,-19.3\,\frac{ft}{s^2}[/tex]
Now what?
I know I need to find [itex]v_f[/itex] and the bottom of the hill and I am probably supposed to use a work-energy equation?
[tex]\sum\,T_1\,+\,\sum\,U_{1\,-\,2}\,=\,\sum\,T_2[/tex]
Please help, thanks.
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