# Kinematics of a Particle

• Nov 11th 2009, 09:37 AM
Viral
Kinematics of a Particle
4). A particle of mass m kg is at rest on a rough plane inclined at an angle above the horizontal. Force X N acts on the particle up the greatest slope of the plane, as shown in the diagram. Find the magnitude and direction of the frictional force when:

a). X = 10, m = 1
b). X = 10, m = 2

I don't really have any idea what to do. The answer for part 1 is 5.1N, and part 2 is 0.2N. Can you help?

http://i34.tinypic.com/2uy4t3p.png
• Nov 11th 2009, 02:07 PM
skeeter
Quote:

Originally Posted by Viral
4). A particle of mass m kg is at rest on a rough plane inclined at an angle above the horizontal. Force X N acts on the particle up the greatest slope of the plane, as shown in the diagram. Find the magnitude and direction of the frictional force when:

a). X = 10, m = 1
b). X = 10, m = 2

I don't really have any idea what to do. The answer for part 1 is 5.1N, and part 2 is 0.2N. Can you help?

http://i34.tinypic.com/2uy4t3p.png

the system is in equilibrium ... forces down the incline = force up the incline

$\displaystyle f_s + mg\sin{\theta} = x$
• Nov 11th 2009, 02:09 PM
Viral
Thanks, I've got it :) .