Newton’s Laws of Motion
❏ Define and differentiate between Newton’ s 3 Laws of motion.
❏ Describe the use of ICT in the investigation of motion.

Newton’s First Law of Motion
Every object continues in its state of rest or uniform motion in a straight line unless made to change by a resultant force. 1. Explain 3 examples that illustrate this law.
2. Answer Qs 1 &2 on page 23 of the text book.

Investigating motion of an object using ICT
Traditionally, data might have been collected using rulers and stop clocks but ICT methods are now available, eg. light gates as in the demonstration shown.
1. Why are light gates better for measuring time.
2. How does the interface give us values for velocity?

Investigating force, mass and acceleration

Newton’s Second Law of Motion
If there is a resultant force there will be a change in velocity, ie. an acceleration.
Newton’s second law states that the acceleration of an object is proportional to the resultant force and inversely proportional to its mass.

resultant force = mass x acceleration
F=ma
1. Answer Qs 1, 2 &3 on page 27 of the text book

They say that, “every action has an equal and opposite reaction”
Our everyday experience tells us that forces come in pairs.
Try to push a car and you can feel it pushing back at you.
Lift a heavy bag and you can feel it pulling you down. The force pairs are equal in size and opposite in direction.
This is Newton’s third law of motion and the basics of rocket science!

Newton’s Third Law