3. NEWTON’S 1ST LAW:
• An object in motion will continue moving and objects at rest will continue to be at rest unless
acted up by an unbalanced force.
• E.g., A soccer ball at rest will tend to stay at rest. It takes an unbalanced force of a kick to change
its motion.
• This is also known as the Law of Inertia.
• Inertia is the property of a body which resists any change in its state of rest or motion.
• Inertia is proportional to mass.
4. CONT
• A soccer ball will remain resting on the grass until a force acts on it
(a kick).
5. CONT…
• Inertia explains many common events, such as why you move forward in your seat when a car
stops suddenly. E,g.,
• When the car stops, inertia keeps you moving forward. E,g.,
6. CONT
• A force, such as the pull of a seat belt, is required to change your motion.
• E,g,.
7. CONT…
• The First Law states that all objects have inertia. The more mass an object has,
the more inertia it has (and the harder it is to change its motion).
• When travelling in a car always wear seat belts. Due to inertia, you will resist
change in your motion.
• When the car you are in is travelling at 100 km/h brakes, your body will keep on
moving at 100km/h.
• This may cause severe injuries or death. Therefore always wear SEAT BELTS.
9. NEWTON’S 2ND LAW:
• The acceleration of an object is directly proportional to the net force
acting on it and inversely proportional to its mass.
• F=ma
F:FORCE
M:MASS
A: ACCELERATION is a measurement of how quickly and
object is changing speed.
10. CONT…
• The greater the force acting on the object, the greater the acceleration of the object.
• The greater the mass of an object , the greater the force needed for the same
acceleration.
• Example 1: Less mass, less force needed.
• Example 2: Greater mass, more force needed.
11. NEWTON’S 3RD LAW:
• For every force acting on an object, there is an equal force acting in the opposite
direction.
• Whenever one object exerts a force on a second object, the second object exerts an equal
and opposite force on the first object. These are known as: Action/ Reaction forces
• For example, as you are sitting down on that chair of yours, gravity is pulling you down
in your seat, but Newton’s Third Law says your seat is pushing up against you with
equal force.
• This is why you are not moving. There is a balanced force acting on you– gravity
pulling down, your seat pushing up.
12. CONT…
• You exert a downward force on the chair, a chair exert an upward force on you.
14. REFERENCES
Bout, K. J., (2008). Available from Slideshare.
at: https://www.slideshare.net/nyennyen/newtons-laws-of-motion-513582?qid=1b1af463-9c05-4609-822d-0829e4dc749d&v=&b=&from_search=8
[Accessed 27 August 2018].
Faner, C., (2013). Available from SlideShare.
at: https://www.slideshare.net/CarlaFaner/force-and-newton-law
[Accessed 27 August 2018].
Grover Cleveland Middle School, (2010). Available from SlideShare.
at: https://www.slideshare.net/jbishopgcms/newtons-laws-of-motion-4940821
[Accessed 31 August 2018].
15. CONT…
Kaushik, P. K., (2009). Availble from Slideshare.
at: https://www.slideshare.net/pvnkmrksk/newtons-laws-of-motion-2587754?qid=ff7a6367-1bca-
44a9-905a-7a9b3a02b7e7&v=&b=&from_search=1
[Accessed 27 August 2018].
Kezia, R., (2016). Available from SlideShare.
at: https://www.slideshare.net/ruthkezia/newton-law-ppt
[Accessed 27 August 2018].
Konia, S., (2012). Available from SlideShare.
at: https://www.slideshare.net/koniasunset/newtons-3-laws-of-motion-14466651
[Accessed 27 August 2018].