Statics

Identifying Static Situations Objects that do not move linearly (translational motion) or rotate (rotational motion) are static

Equations

Example 40º A box of mass 10 kg is placed 2 m from the left end of a 7 m long horizontal beam. The beam has a mass of 20 kg and is supported by a cable that makes a 40º angle to the beam. What is the tension in the cable?

40º FxFx FyFy 98 N 196 N T

Ladder mg N FfFf RFfFf Mg

Ladder Problem A 20 m ladder (mass of 15 kg) is leaning against a frictionless wall and makes a 60 degree angle to the horizontal. What is the minimum coefficient of friction needed between the floor and the ladder to keep the ladder from slipping?

mg N FfFf R

R θ 90-θ θ B