# Newtons Law NEXT Newtons Laws Newtons First Law

• Slides: 17

Newton’s Law NEXT

Newton’s Laws Newton’s First Law u. Law of Inertia F Newton’s Second Law u. F = ma F Newton’s Third Law u. Action Reaction F Law of Universal Gravitation F NEXT PREVIOUS

Mass F …is measured in kilograms. F …is the measure of the inertia of an object. F Inertia is the natural tendency of a body resist changes in motion. NEXT PREVIOUS

Force F …the agency of change. F …changes F …is the velocity. a vector quantity. F. . . measured NEXT PREVIOUS in Newton’s.

Newton’s First Law F “A of Inertia body remains at rest or moves in a straight line at a constant speed unless acted upon by a force. ” NEXT PREVIOUS

Newton’s First Law F No mention of chemical composition F No mention of terrestrial or celestial realms F Force required when object changes motion F Acceleration is the observable consequence of forces acting NEXT PREVIOUS

Newton’s Second Law The Sum of the Forces acting on a body is proportional to the acceleration that the body experiences SF a S F = (mass) a NEXT PREVIOUS

Net Force NEXT PREVIOUS

Newton’s Third Law F Action-Reaction F For every action force there is an equal and opposite reaction force NEXT PREVIOUS

The Law of Gravity F Every mass exerts a force of attraction on every other mass. F The math… FG = 6. 67 10 -11 N·m 2/kg 2 NEXT PREVIOUS

Gravity Questions F Did the Moon exert a gravitational force on the Apollo astronauts? F What kind of objects can exert a gravitational force on other objects? NEXT PREVIOUS

Gravity Questions F The constant G is a rather small number. What kind of objects can exert strong gravitational forces? F If the distance between two objects in space is doubled, then what happens to the gravitational force between them? NEXT PREVIOUS

Weight F The weight of an object FW is the gravitational force acting downward on the object. F FW = NEXT mg PREVIOUS

Tension (Tensile Force) F Tension is the force in a string, chain or tendon that is applied tending to stretch it. F FT NEXT PREVIOUS

Normal Force F The normal force on an object that is being supported by a surface is the component of the supporting force that is perpendicular to the surface. F FN NEXT PREVIOUS

Coefficient of Friction F Kinetic Friction • Ff = mk FN F Static Friction • Ff ms FN F In NEXT most cases, mk < ms. PREVIOUS

On to problems. . .