Transcript Situation Diagram Free-body diagram

Inclined Planes and Net Force
Renate Fiora
How do we figure out net force?
• Similar to any other time, when an object is
on an inclined plane, we must combine all the
forces acting on it to find the resulting net
force.
• There are three general cases we encounter:
– When the object is at rest.
– When the object is moving at a constant velocity.
– When the object is accelerating.
Object at Rest
Free-body diagram
Situation Diagram
+y / 
FN
FN
Fnet = 0
Ff
Ff
+x / 
FW
FW
Object at Constant Velocity
Situation Diagram
+y / 
Free-body diagram
FN
FN
Ff
FA
Fnet = 0
Ff
FA
+x / 
FW
FW
The applied force is in green to show that it may not be present in all
situations. It may only be the parallel component of the object’s weight
accelerating it.
The object does not necessarily have to moving in one direction or
another, but the directions of the force vectors will change accordingly.
Object Accelerating
Situation Diagram
+y / 
Free-body diagram
FN
FN
Fnet
Ff
FA
Ff
FA
+x / 
FW
FW
The applied force is in green to show that it may not be present in all
situations. It may only be the parallel component of the object’s weight
accelerating it.
The object does not necessarily have to moving in one direction or
another, but the directions of the force vectors will change accordingly.