4 Pre Test Lecture Force Physics IVC

# 4 Pre Test Lecture Force Physics IVC - Newton's First Law...

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

Newton’s First Law Law I Everybody continues in its state of rest, or in uniform straight- line motion, unless a force acts upon it. Object at rest remains at rest unless a force acts upon it. Force acted on red ball: Cause and effect.

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

View Full Document
Newton’s Second Law Σ F = m a The sum of forces on an object, cause the object to accelerate—velocity changes with time .
To every action there is a reaction. Newton’s Third Law: Force of hand pushes on wall. Wall Pushes back with the same force, but not same accelerations would result if wall moved. Why not?

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

View Full Document
Applying Newton’s Laws The mathematical expression above says: the sum of forces on the object equals the mass times acceleration of the object. Σ F = m a ΣF x = ma x ΣF y = ma y ΣF z = ma z Note if the object is in equilibrium the all sums of forces equal zero, i.e. no acceleration: Σ F = m a = 0 Force is a vector. We have learned vectors must be analyzed component-wise.
1) Write down what you are trying to solve? 2) Draw a picture of problem 3) Write down knowns and initial conditions of problem 4) Choose appropriate coordinate system 5) Draw free body diagrams 6) Write out F = ma in component form 7) Draw component forces 8) Solve F = ma for acceleration or other related variables and information. Setup for Force problems: E.g. How much force is needed? A = 5, B = 2x, z = 9 x y F x = ma x F F x

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

View Full Document
Physical example of Newton’s first law: An object at rest remains at rest. An object in motion continues in straight-line motion unless a force acts on the object.
Since no force acts on object the object moves in a straight- line.

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

View Full Document
Newton’s 1 st law: The Law of Inertia, apparently was realized by many other natural philosophers independently. Inertia of motion was described in the third century BC in the Mo Tzu , a collection of Chinese philosophical texts.
Mozi (470 BCE–ca. 390 BCE), was a philosopher who lived in China during the Hundred Schools of Thought period (early Warring States Period). He founded the school of Mohism and argued strongly against Confucianism and Daoism. In contrast to those of Confucius, Mozi's moral teachings emphasized self-reflection and authenticity rather than obedience to ritual. By reflecting on one's own successes and failures, one attains true self-knowledge rather than mere conformity with ritual. 400s-300s BCE

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

View Full Document
among many things formulated the law of inertia. Descartes: 1596 –1650 Not only did Descartes provide the first distinctly modern formulation of laws of nature and a conservation principle of motion, but he also constructed what would become the most popular theory of planetary motion of the late seventeenth century. Descartes is often regarded as the first modern thinker to provide a
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 10/05/2011 for the course PHYS 4A taught by Professor Ernest during the Summer '10 term at Irvine Valley College.

### Page1 / 65

4 Pre Test Lecture Force Physics IVC - Newton's First Law...

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

View Full Document
Ask a homework question - tutors are online