1. Any push or pull on an object

2. TERMS Concurrent forces- Two or more forces that act through a single point. Resultant Force- A single force that represents the sum of two or more forces.

3. Components of force- the two perpendicular forces that will give the resultant force F x = F cos Ѳ F y = F sin Ѳ Frictional force- (F f ) Any force that opposes a motion.

4. Equilibrium force (F e )-Force that is equal to the resultant force but in the opposite direction. Net force is zero and the object is at rest or traveling at a constant velocity. Normal Force (F n )- Force between contact surfaces

5. Spring Force (F s ) – force due to the stretch or compression of a spring. Centripetal force (Fc)- Force produced by an object traveling in a circular path

6. PARALLEL FORCES If the gravitational force is equal to the cable force, the elevator is traveling at a constant velocity or its at rest. If gravitational force is greater, it accelerates downward If cable force is greater, it accelerates upward

7. If the gravitational force is equal to the cable force, the elevator is traveling at a constant velocity or its at rest. If gravitational force is greater, it accelerates downward. PARALLEL VECTORS If cable force is greater, it accelerates upward

8. FORCES AT RIGHT ANGLES Two tug boats are pulling a barge by tow lines. One pulls north with a force of 10,000N and the other pulls east with a force of 7,500N. What will be the resultant force on the barge? c 2 = a 2 + b 2 Tan Ѳ = 10,000 c 2 = 10,000N 2 + 7500N 2 7500 c = 12,500N Ѳ = 53° C = 12,500N @ 53° NE

9. EQUILIBRIUM FORCE If the tug boats and barge are not moving, what force is the barge exerting? F = 12,500N @ 53°NE F e = 12,500N @ 233°SW

10. COMPONENTS OF FORCES A girl pulls a sled with a force of 100N. If the rope is held at 37° find the horizontal and vertical components of the applied force. F x = F cosѲ F x = 100N cos 37° F x = 79.9N F y = F sinѲ F y = 100N sin 37° F y = 60.2N FyFy