Motion and Inertia: Galileo and Newton's Laws

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Questions and Answers

What is the SI unit of velocity?

kilometre per hour

metre per hour

kilometre per minute

metre per second (correct)

What is the tendency of an object to resist change when in motion or when at rest?

Gravity

Acceleration

Momentum

Inertia (correct)

What is the term for the change in velocity with a given time?

Free Fall

Acceleration (correct)

Velocity

Motion

What is an example of motion with uniform acceleration?

Free Fall Signup and view all the answers

What is the reason why objects in a vacuum fall at the same rate?

Because of the absence of air Signup and view all the answers

What is the law that explains why objects are moving and why they do not move?

Newton's Law of Motion Signup and view all the answers

What was Aristotle's view on the relationship between an object's weight and its falling speed?

Heavier objects fall faster than lighter ones. Signup and view all the answers

What is the main difference between Galileo's and Aristotle's views on force and motion?

Aristotle believed force is required for constant velocity, while Galileo did not. Signup and view all the answers

What was the main purpose of Galileo's Experiment II?

To measure the acceleration of an object in free fall. Signup and view all the answers

According to Galileo, what is the main characteristic of an object in a vacuum?

It will fall at the same rate as in air. Signup and view all the answers

What is the concept that states an object at rest will remain at rest, and an object in motion will continue to move, unless acted upon by an external force?

Inertia Signup and view all the answers

What was the main limitation of Galileo's Experiment I?

He could not measure the distance travelled. Signup and view all the answers

What is the acceleration of an object in free fall near the surface of the earth?

9.8 m/s2 Signup and view all the answers

Which scientist believed that an object in motion will continue to move without friction?

Galileo Signup and view all the answers

What is the term for an object's tendency to resist changes in its motion?

Inertia Signup and view all the answers

What is the unit of measurement for the acceleration of an object?

m/s2 Signup and view all the answers

Which of the following is an example of horizontal motion?

A rolling ball Signup and view all the answers

What is the term for the downward force that pulls objects towards the ground?

Gravity Signup and view all the answers

Study Notes

Galileo and Newton's Contributions

Galileo is considered the Father of Modern Science.
He believed that objects that are heavy and light will fall at the same time in a vacuum, where there is no air.
Velocity is expressed in meters per second (m/s).

Newton's Laws of Motion

Sir Isaac Newton formulated laws explaining why objects move or don't move.
Inertia is the tendency of an object to resist change when in motion or at rest.
Newton's first law of motion states that an object at rest will stay at rest, and an object in motion will continue to move, unless acted upon by an external force.
There are three types of inertia: inertia at rest, inertia of motion, and inertia of direction.

Motion

Motion is defined as the ability of an object to change its position with respect to its surroundings in a given time.
Free fall is an example of motion with uniform acceleration.
Acceleration is the change in velocity over a given time.
Speed is the distance traveled by an object divided by the time taken to travel that distance.

Aristotle's vs Galileo's View of Motion

Aristotle believed that heavier objects fall faster than lighter ones and that force is required for constant velocity.
Galileo disagreed with Aristotle's view and believed that objects in a vacuum will fall at the same time, regardless of their weight.
Galileo's view states that force is not necessarily required for violent motion or for an object moving at constant velocity.

Galileo's Experiments

Galileo dropped two different weights of cannon balls from the Leaning Tower of Pisa and they fell at the same time.
He used an inclined ramp to measure the acceleration of an object and discovered that objects accelerate at the same rate, regardless of their size and speed.

Free Fall and Gravity

Freely falling bodies undergo constant acceleration, known as free fall.
The free fall acceleration is represented by the symbol g, which is approximately 9.8 m/s² at the surface of the Earth.
Gravity leads objects to accelerate at a constant rate.

Horizontal and Vertical Motion

Horizontal motion has a constant value, represented by the x-axis, and is characterized by rolling balls and inertia.
Vertical motion has a changing value, represented by the y-axis, and is characterized by free fall.

Dispersion and Light

Dispersion is the separation of visible light into its different colors.
The Law of Reflection is always observed, regardless of the orientation of the object.
Light is an electromagnetic radiation that travels through space as vibrating or oscillating waves at a speed of 3.0 x 10^8 m/s in a vacuum.