1. Force Chapter 4 (Ewen et al. 2005) Objectives: Related force and the law of inertia. Apply the law of acceleration.

2.  What causes an object to accelerate?  Answer: forces  Force is any push or pull  Forces, when unbalanced, change the motion of an object.  When balanced, motion stays constant.

3.  Newton (N) in the SI system  Pounds (lb) in the English system  4.45 N = 1 lb

4.  Newton discovered three relationships or laws between forces and motion.  Law of inertia: Newton’s first law  Law of acceleration: Newton’s second law  Law of action and reaction: Newton’s third law

5.  An object in motion continues that motion with the same velocity, and a body a rest continues at rest unless an unbalance force acts on it.

6.  The property of a body that causes it to remain at rest if at rest or to continue moving with a constant velocity.  It is an object’s resistance to a change in motion.  Inertia is directly related to mass of an object.  More mass, more inertia  Units for mass: kilogram (SI), slug (US)  1kg = 0.0685 slug

7.  Relates the applied force, the mass, and the acceleration of an object.  It states that  Acceleration is directly proportional to force  And, inversely proportional to mass.  Units for force  1 N = 1 kg m/s 2  1 lb = 1 slug ft/s 2

8.  What force is necessary to produce an acceleration of 6.00 m/s 2 on a mass of 5.00kg?

9.  What force is necessary to produce an acceleration of 2.00 ft/s 2 on a mass of 3.00 slugs?

10.  Find the acceleration produced by a force of 500 N applied to a mass of 20.0 kg.