Frc21 Simple Incline Plane

A simple 30^o incline plane has the 30 kg and 50 kg masses as shown.

Find the acceleration and the tension in the cord?

Guessing at the direction of the acceleration is not so simple in this problem. Don't agonize over it. Choose counterclockwise and proceed with the vector diagram. The 30 kg mass presents no problem. For the 50 kg mass we need the component of the gravitational force down the plane.

The component of the 490 N down the plane is 245 N. Now assuming the counterclockwise rotation write

Again T₁ = T₂ so add

and

Copyright © Robert M. Oman 2004