This problem is giving me issues. I don't think I'm using the right equations....(adsbygoogle = window.adsbygoogle || []).push({});

Problem:

A 2.0-kg mass is released from rest at the top of a plane inclined at 20 degrees above horizontal. The coefficient of kinetic friction between the mass and the plane is 0.20. What will be the speed of the mass after sliding 4.0 m along the plane.

A) 2.2 m/s

B) 3.0 m/s

C) 3.5 m/s

D) 5.2 m/s

Work:

Here is what I tried.

Mass= 2.0kg

Coefficient of Kenetic Friction= 0.20

Displacement= 4m

Weight= 9.8*2=19.6N

W=F*d*cos 0

W=19.6*4*cos(20)

W=73.67

W sub NET= change in KE

73.67=1/2*2*v(squared)

v=8.58m/s

That is not one of my choices :uhh:

Any help would be fantastic. Thanks in advance.

Kirk

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# Homework Help: Work Problem I think

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