2. Newton’s First Law
(law of inertia)
An object at rest will
continue to stay at rest
unless an outside force
acts on it and …
3. Newton’s First Law
(law of inertia)
an object in motion will
continue to stay in
motion at constant speed
in a straight line unless
an outside force
acts on it
4. Newton’s First Law
(law of inertia)
FORCE is a push or a
pull applied to an object
that will cause it to start
moving, stop moving or
change its speed or
direction
5. Newton’s First Law
(law of inertia)
FRICTION is the force
that acts in the opposite
direction of the motion of
the object
6. Newton’s First Law
(law of inertia)
MASS is the measure of the
amount of matter in an object
measured in grams (g)
or kilograms (kg)
7. Newton’s First Law
(law of inertia)
WEIGHT is a measure of the
force of gravity on the mass of
an object
measured in Newtons (N)
9. Newton’s First Law
(law of inertia)
INERTIA is a property of an
object that describes how hard
it is to change the motion of
the object
more mass means more inertia
10. REVIEW QUESTIONS
1. What is the difference between mass
and weight?
3. Which has more mass, 12 g of feathers
or 12 g of lead?
5. When an astronaut is living on the
International Space Station, what
happens to his mass?
11. REVIEW QUESTIONS
1. What would the mass of a dog be if it
has a weight of 100N?
3. What would the weight of an apple be if
it has a mass of 1.5 kg?
5. What is a force?
12. REVIEW QUESTIONS
1. What is friction?
3. What causes friction on a moving object?
