Hey, this is my first time posting on PhysicsForums! I usually go through the archives but I couldn't find a problem like this.(adsbygoogle = window.adsbygoogle || []).push({});

Two blocks m1 and m2 with masses 50 kg and 100 kg respectively are connected by a string over a pulley that is frictionless with negligible mass. The 50 kg block slides on a 37 degree incline that has a coefficient of kinetic friction of .25. The system is released from rest with a force of 25 N pulling down on the 100 kg block. Calculate the change in kinetic energy of block m1 as it moves a distance of 20 m up the incline.

I think I'm supposed to use this:

[tex]\Delta K + \Delta U_{g1}+\Delta U_{g2} = W_{friction} + W_{applied}[/tex]

So far I have

[tex]W_{friction} = -\mu m_{1}gcos(\Theta)d [/tex]

[tex]W_{applied} = Fd [/tex]

[tex]\Delta U_{g1} = m_{1}gdsin(\Theta) [/tex]

[tex]\Delta U_{g2} = m_{2}gd[/tex]

The answer is supposed to be 4090 J but when I crank out the numbers I don't get that.

What am I missing?! I've stared at this problem for too long. Thank for any help.

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# Homework Help: Kinetic Energy on Pulley/Incline System

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