Chapter Four Forces and Motion - Chapter Four: Force and...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter Four: Force and Chapter Four: Force and Motion Motion Learning Objective: To define the concept of Learning Objective: To define the concept of force. force. Learning Objective: To apply the relationships Learning Objective: To apply the relationships known as Newton’s Laws. known as Newton’s Laws.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Newton’s Laws Guided Study Newton’s Laws Guided Study Newton’s First Law An object at rest remains at rest, unless acted upon by a net force . An object in straight line motion at constant speed will continue in that manner unless acted upon by a net force .
Background image of page 2
Newton’s Second Law Newton’s Second Law An object of mass, m, will experience an acceleration, a , given by the ratio of the net applied force, F net , divided by the mass. The units of force are given by the units of the terms in the equation, F net = ma N = kg m/s 2 Where N is the Newton unit.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Weight Weight Your weight is the force of gravity on you. What is the acceleration of gravity? g = 9.8 m/s 2 So, that means that your mass, m, experiences a force of F = m g We call this the object’s weight, W W = mg
Background image of page 4
Newton’s Third Law Newton’s Third Law For every action there is an equal and opposite reaction.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Consider the following situation: You are standing in the middle of the room. Are there any forces acting on you? Is there net force acting on you? Draw the forces acting on you. Justify your answer by referring to Newton’s Laws.
Background image of page 6
Now remove the floor and draw the forces acting on you. What is your state of motion now? Characterize it by stating something that we can calculate.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Free Body Diagrams Free Body Diagrams An FBD distills the problem’s complexity down to only those actions that are interacting with the object of interest.
Background image of page 8
The maximum load that can safely be supported The maximum load that can safely be supported by a rope in an overhead hoist is 400 N. What is by a rope in an overhead hoist is 400 N. What is the maximum acceleration that can safely be given the maximum acceleration that can safely be given to a 25-kilogram object being hoisted vertically to a 25-kilogram object being hoisted vertically upward? upward? Free Body Diagram a F rope W F rope =400 N W = mg = 25 kg * 9.8 m/s 2 A = F net /m = (400 N – 245 N)/25 kg = 6.2 m/s 2
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
An object with a mass of 4.0 kg travels with a An object with a mass of 4.0 kg travels with a constant velocity of 4.8 m/s northward. It is then constant velocity of 4.8 m/s northward. It is then acted on by a force of 6.5 N in the direction of motion acted on by a force of 6.5 N in the direction of motion and a force of 9.5 N to the south, both of which and a force of 9.5 N to the south, both of which
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/05/2009 for the course PHYSICS Intro taught by Professor Dziembowski during the Spring '09 term at Community College of Philadelphia.

Page1 / 41

Chapter Four Forces and Motion - Chapter Four: Force and...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online