Transcript Forces, Motion and Roller Coasters!

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.
Sailors

Inertia is the tendency of an object to resist
changing its motion.
Inertia Video

More mass = more inertia (harder to change their
state of motion – moving or still!)
Discs
Vocabulary

Inertia
– tendency of an object to resist changing its
motion

Force (Measured in Newton’s!)
– measure of a push or pull
Balanced Forces

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
– 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 unbalanced
forces are acting on a rollercoaster ride.

Vocabulary
~ Balanced Force ~
~ Unbalanced Force ~
Forces that can change an objects
 Friction – force opposing
object motion
motion
– air resistance
– starting
– sliding
– rolling

Gravity
– force accelerating
objects towards
the center of mass
(Earth = 9.8 m/s2)
MOMENTUM
Measure of mass in motion
 momentum = mass x velocity (P = mv)

Collision & Momentum Simulation