Download Examples of Inertia

8.P.2A.3
September 09, 2016
8.P.2A.3
Newton's First Law: Inertia
Construct explanations for the
relationship between the mass of
an object and the concept of
inertia (Newton's First Law of
Motion)
The velocity of an object will
remain constant unless a net
force acts on it.
Inertia
The tendency for
objects to stay in
motion if they are in
motion
Tendency for
objects to stay at
rest if they are at
rest
The more mass an
object has, the harder it
is to stop it
The more mass
an object has,
the harder it is to
get it to move
If an object has a large amount of inertia
(due to large mass)
– It will be hard to slow down or
speed it up if it moving.
– It will be hard to make it start
moving if it is at rest.
– It will be hard to make it change
directions.
In other words, the more
mass an object has, the more
inertia it has
Examples of Inertia
• It causes a passenger in a car to
continue to move forward even
when the car has stopped
• The reason it is harder to push a
wheelbarrow full of bricks rather
than an empty one
• Inertia is the reason it is harder
to stop a big truck going 55 mph
than a small car going 55 mph
Which type of car, a heavier one or
a lighter one, needs more force to
slow down with the same
deceleration?
The heavier car needs to have
more braking force to have the
same deceleration because of
its mass.
8.P.2A.3
LAB (Around and Around)
1. Suspend the ball in front of you and swing
it in a horizontal circle, keeping it 2-3cm
above the floor.
2. Let go of the thread and observe the
direction in which the ball rolls.
3. Repeat this several time, letting go of the
thread at different points.
4. At what point do you need to let go of the
thread if you want the ball to roll directly
away from you? Toward you?
5. Draw a diagram as part of your answer.
September 09, 2016
Remember as you are going
through the lab, that inertia
is not a force but a way to
describe motion
8.P.2A.3
September 09, 2016