Parallel force system

Parallel vertical forces acting on an airplane in straight and level flight. Lift from the main wing (Pz) is balanced by the weight of the airplane (mg) and the down-force on the horizontal stabilizer (Pzh). source ↗

In engineering, a parallel force system is a type of force system where in all forces are oriented along one axis.

An example of this type of system is a see saw. In a see saw, the children apply the two forces at the ends, and the fulcrum in the middle gives the counter force to maintain the see saw in a neutral position.

Another example are the major vertical forces on an airplane in flight.

References

Kumar, K.L. (2003). Engineering Mechanics,3e (in Dutch). McGraw-Hill Education (India) Pvt Limited. p. 90. ISBN 978-0-07-049473-2. Retrieved September 10, 2017.
Blake, Alexander (1985). Handbook of Mechanics, Materials, and Structures. John Wiley & Sons. p. 128. ISBN 9780471862390.
R.K. Bansal (December 2005). A Textbook of Engineering Mechanics. Laxmi Publications. p. 25. ISBN 978-81-7008-305-4.
M. N. Shesha Prakash; Ganesh B. Mogaveer (30 July 2014). Elements of Civil Engineering and Engineering Mechanics. PHI Learning Pvt. Ltd. p. 25. ISBN 978-81-203-5001-4.