SACE Stage 1 Conceptual Physics 3 Newtons First

SACE Stage 1 Conceptual Physics 3. Newton’s First Law of Motion Inertia

Newton’s Law of Inertia n Every object continues in its state of rest, or of motion in a straight line at constant speed unless it is compelled to change that state by forces exerted upon it.

Newton’s Law of Inertia

Newton’s Law of Inertia – Question 1 n If suddenly the force of gravity of the sun stopped acting on the planets, in what kind of path would the planets move?

Newton’s Law of Inertia – Question 1 Answer n If suddenly the force of gravity of the sun stopped acting on the planets, in what kind of path would the planets move? n The planets, like any objects, would move in a straight-line path if no forces acted upon them.

Mass – A Measure of Inertia n Mass is not Volume is a measure of space. Measured in m 3. n Mass is not Weight is a measure of the gravitational force on an object. Measured in N.

Mass – A Measure of Inertia n Mass is the quantity of matter in a body. n 1 Kg Weighs 9. 8 N

Review n According Newtons First law of Motion – The Law of Inertia – every object continues in its state of rest or of motion in a straight line at constant speed unless forces cause it to change its state.

Review n Inertia is the resistance an object has to change in its state of motion. Mass is a measure of Inertia. n Mass is not the same as Volume. n Mass is not the same as Weight. n The mass of an object depends on the amount and type of matter in it, but does don’t depend on the location of the object. n The Weight of an object is the gravitational force on it and depends on the location. n