Download File topic 6 - newton`s 1st law of motion

The Laws of Motion & Force!
Question:
What is Inertia?
Answer:
The resistance an object
has to being moved from
rest!
• Inertia is directly proportional to the MASS of an
object.
• The more massive an object is, the more Inertia it
possesses.
Momentum!
Question:
What is Momentum?
Answer: The ability an object has to
keep on moving in a straight
line at constant velocity.
• Symbol:
p
(lower case)
Momentum is directly related to mass and velocity, so:
Newton’s 1st Law of Motion!
(also referred to as the Law of Inertia)
Objects at rest tend to stay at rest (Inertia);
objects in motion tend to stay in motion,
(momentum) at a constant velocity in a
straight line, unless acted upon by an
unbalanced, external force.
The Laws of Motion & Force!
Question:
What is a Force?
Answer: Any influence which CAN
cause an object to accelerate
(Push or Pull on an object)
• Forces are vector quantities - you cannot push or
pull on an object without doing so in some
direction!
The Laws of Motion & Force!
Recall the four fundamental interactions (forces)!
Strong force
Weak force
These are Nuclear
Forces and occur at
the subatomic level,
so their effects cannot
be seen with the
naked eye. Thus,
most people are
unaware of them.
Electromagnetic force Gravitational force
These Forces can occur on objects massive
enough to be seen, and are readily
observable. Gravity is the force responsible
for planetary motions and gravitational
accelerations. EVERYTHING ELSE is a
manifestation of the Electromagnetic Force,
i.e. pushes, pulls, surface tensions,
electrostatic and magnetic attractions and
repulsions, light and radio waves, etc.