Transcript Newton*s Laws of Motion

INERTIA

An object will
remain at rest or in
constant motion
unless acted upon
by an unbalanced
force.
“THE OLD TABLECLOTH TRICK”
WHICH HAS MORE MASS?
WHICH HAS MORE MASS?
LESS MASS = LESS INERTIA

The skier does not have a
lot of mass therefore has
LESS inertia; & is easier to
stop
MORE MASS = MORE INERTIA

The car has MORE MASS
therefore has A LOT OF
INERTIA; & is harder to
stop
•Finger applies a force to a card causing it to move
•Penny STAYS at rest (over the cup) due to inertia
•Gravity causes the penny to fall into cup

What happened to the
spinning hardboiled
egg when you tapped
it?

What happened to the
spinning raw egg when
you tapped it & let go?
 The egg continued to
spin
 The egg stopped
spinning


Why?
 The egg is a solid unit
and the finger applied
enough force to change
the inertia
Why?
 The liquids inside the
egg were in motion &
wanted to stay in motion
due to inertia

Which cup was easier to keep standing?
 The cup (more massive one) because it has more
inertia
 The empty cup was harder to keep standing
because it has less mass therefore less inertia
Vectors- arrows that show the direction
& strength (magnitude) of a force
•Longer Arrow =
Stronger Force
•Shorter Arrow =
Weaker Force
•Forces measured
in Newtons (N)

Cancel each other
out so net force = O

Results in NO
MOTION or NO
CHANGE in motion

Forces that don’t cancel & the object moves in the direction of
the stronger force.

DIFFERENT directions, SUBTRACT the forces

SAME direction, ADD the forces.

An object acted on by an unbalanced force
accelerated in the direction of the force

Force= mass x
acceleration



Mass (kg or grams)
Acceleration (m/s2)
1 Newton= force
needed to move 1 kg 1
m/s2

More Mass = More
Gravity
 Earth has more gravity
than Moon b/c Earth is
more massive

More Distance = Less
gravity

Acceleration due to
Gravity = 9.8 m/s2