Newton’s First Law of Motion Newton’s First Law of Motion

Newton’s First Law – Law of Inertia Objects in motion will stay in motion at a constant velocity and objects at rest will stay at rest unless acted upon by an outside force. Objects in motion will stay in motion at a constant velocity and objects at rest will stay at rest unless acted upon by an outside force. Sailors Inertia is the tendency of an object to resist changing its motion. Inertia is the tendency of an object to resist changing its motion. Inertia Video Inertia Video More mass = more inertia (harder to change their state of motion – moving or still!) More mass = more inertia (harder to change their state of motion – moving or still!) Discs

Vocabulary Inertia Inertia –tendency of an object to resist changing its motion Force (Measured in Newton’s!) Force (Measured in Newton’s!) –measure of a push or pull

Balanced Forces Balanced force = no acceleration Balanced force = no acceleration –A car traveling down the highway at a CONSTANT velocity –A ball sitting on the top of a desk (at rest) Anything moving at a constant velocity OR is sitting perfectly still has forces acting on it that are BALANCED.

Unbalanced Force Unbalanced force = acceleration Unbalanced force = acceleration –Causes object in motion to change speed &/or direction –causes resting object to move

Think! Give 1 example of when only balanced forces are acting on a vehicle. Give 1 example of when only balanced forces are acting on a vehicle. Give 1 example of when unbalanced forces are acting on a rollercoaster ride. Give 1 example of when unbalanced forces are acting on a rollercoaster ride. Vocabulary ~ Balanced Force ~ ~ Unbalanced Force ~

Forces that can change an objects motion Friction – force opposing object motion Friction – force opposing object motion –air resistance –starting –sliding –rolling Gravity Gravity – force accelerating objects towards objects towards the center of mass the center of mass (Earth = 9.8 m/s 2 )

MOMENTUM Measure of mass in motion Measure of mass in motion momentum = mass x velocity (P = mv) momentum = mass x velocity (P = mv) Collision & Momentum Simulation