# physics, force stuff

• Sep 27th 2008, 08:36 PM
sarabolha
physics, force stuff
Mass m1=25.7 kg is on a horizontal surface, connected to mass m2= 5.10 kg by a light string as shown. The pulley has negligible mass and no friction. A force of 222.5 N acts on m1 at an angle of 30.9o.The coefficient of kinetic friction between m1 and the surface is 0.233. Determine the upward acceleration of m2.

http://nplq1.phyast.pitt.edu/res/msu...2_tenpully.gif

• Sep 27th 2008, 11:40 PM
Kai
Quote:

Originally Posted by sarabolha
Mass m1=25.7 kg is on a horizontal surface, connected to mass m2= 5.10 kg by a light string as shown. The pulley has negligible mass and no friction. A force of 222.5 N acts on m1 at an angle of 30.9o.The coefficient of kinetic friction between m1 and the surface is 0.233. Determine the upward acceleration of m2.

http://nplq1.phyast.pitt.edu/res/msu...2_tenpully.gif

As shown >> where is it ?
• Sep 28th 2008, 06:48 AM
sarabolha
its just making a referece to the picture, the light string is what is connecting the two masses...
• Sep 28th 2008, 07:00 AM
skeeter
I'm guessing $\displaystyle m_2$ is a hanging mass.

let T = magnitude of the tension in the string between $\displaystyle m_1$ and $\displaystyle m_2$.

F = magnitude of the applied force on $\displaystyle m_1$

N = magnitude of the normal force on $\displaystyle m_1$ by the horizontal surface

net force on $\displaystyle m_2$ ...

$\displaystyle T - m_2g = m_2a$

net force on $\displaystyle m_1$ ...

$\displaystyle F\cos(30.9) - \mu N - T = m_1a$

where ...

$\displaystyle N = m_1g - F\sin(30.9)$

$\displaystyle m_1$ and $\displaystyle m_2$ will experience the same magnitude of acceleration ... solve the system of equations for "a".