Newton's Laws 
May The Force Be With You (by: Jennifer Hart) 

Sir Isaac Newton was one of the greatest scientists and mathematicians that ever lived. He was born in England on December 25, 1643. He was born the same year that Galileo died. He lived for 85 years. Isaac Newton was raised by his grandmother. He attended Free Grammar School and then went on to Trinity College Cambridge. Newton worked his way through college. While at college he became interested in math, physics, and astronomy. Newton received both a bachelors and masters degree. 

While Newton was in college he was writing his ideas in a journal. Newton had new ideas about motion, which he called his three laws of motion. He also had ideas about gravity, the diffraction of light, and forces. Newton's ideas were so good that Queen Anne knighted him in 1705. His accomplishments laid the foundations for modern science and revolutionized the world. Sir Isaac Newton died in 1727 (Louviere, 2008).

(Kneller, 1689)


A lock of Newton's hair in Trinity College, Cambridge.

(Scientific-web, 2008)

Trinity College.jpg

Trinity College, Cambridge (Lipoff, 2004)


A Brief History of Isaac Newton's Apple Tree

Growing in a courtyard garden in the Physics Department here in the University of York we have a grafted cutting from an ancient apple tree which still survives in Newton's garden at Woolsthorpe Manor, his birthplace in Lincolnshire. This is the tree from which it is reputed that Newton saw an apple fall in the late summer of 1666 and which caused him to speculate upon the nature of gravitation. Our tree was given to us by Kew Gardens in 1976.

Newton's Apple Tree growing in the courtyard at the Physics Department, University of York.

The account of Isaac Newton's discovering the principle of universal gravitation by observing the fall of an apple is very well known and usually dismissed as apocryphal. However little can be further from the truth for Newton gave this account of his discovery to several acquaintances which include Voltaire (French philosopher and essayist), John Conduitt (his assistant at the Royal Mint) Catherine Barton (his niece) William Stewkeley (friend and antiquarian), Christopher Dawson (a student at Cambridge) amongst others. The first written account appears in notes on Newton's life collected by John Conduitt in 1726 the year of Newton's death. It states that;


he first thought of his system of gravitation which he hit upon by observing an apple fall from a tree,
The incident occurring in the late summer of 1666.
In other accounts it is stated that Newton was sitting in his garden at Woolsthorpe Manor near Grantham in Lincolnshire when the incident occurred.
The first account of their being a specific tree in his garden from which Newton saw the apple fall appears in the book "A History of the Town and Soak of Grantham", by Edmund Turnor FRS (1806) in which there appears the footnote on p160:
The tree is still remaining and is showed to strangers.
His brother the, Rev. Charles Turnor, drew the accompanying picture of the tree in 1820 showing its position with respect to the manor house.

Charles Turnor drawing of the apple tree showing its position with respect to the manor house

Although Newton did not specify from which tree he observed the apple fall it turned out that it was the only apple tree growing in his garden and thus it selected itself.
This was first mentioned by Sir David Brewster when he visited the house in 1830, the account of which was given by George Forbes (Professor of Physics University of Glasgow)

George Forbes account of Sir David Brewster's visit to the house in 1830.

The tree had been cared for since the 1750's by generations of the Woolerton family, who were tenant farmers who lived in the house from 1733 to 1947. Despite all their efforts to prop the aged tree up, it blew down in a storm in 1816. Some branches were removed but the major portion of the tree was left and re-rooted. The surprising fact is that this tree is still growing at Woolsthorpe Manor today and now must be over 350 years old (Keesing, 2009).

Newton's Apple Tree growing in the courtyard at the Physics Department, University of York (Keesing,  2009).

Cranbury House
Cranbury House
In Cranbury Park, near Winchester. This house was built in 1780 but the park
was originally the home of Sir Isaac Newton (Keesing, 2009).

A sketch by Newton of one of his prism experiments.A sketch by Newton of one of his prism experiments (Thomas, 2008).

If we shine a beam of light on a prism the light splits into the colors that make it up. The same happens when sunlight passes through water droplets and we see a rainbow (Thomas, 2008).

Earth floating in space

The Earth viewed from the Moon.
Photo: NASA


Left to grow up with his grandmother when he is two, described as "idle and inattentive" in school, Isaac Newton begins to show a passion for poetry and ideas when he is seventeen. He attends Cambridge University, studying Greek, Latin, Hebrew, and ancient history, and is said to be uninterested in mathematics until he is twenty, when he picks up a book on astrology at a fair, and tries to make sense of its math. His genius is quickly revealed, as well as his aptitude for hard work, but it is not until Cambridge closes due to the plague and he returns home that he makes the discoveries of his miraculous year.

In 1666, at the age of twenty-four, Newton laid the foundations for calculus, an indispensable tool that will allow him to calculate planetary motion and gravitational force over time. Calculus can be applied to any situation in which a summing process is used to approximate quantities for work, volume, motion, gravitation, or arc. It is indispensable for modern engineering and building. A reclusive man, Newton describes calculus in 1671, but does not publish his discovery, and Gottfried Liebniz, working and publishing nine years later, is also considered an inventor of calculus.
Not yet 25, Newton establishes a theory of light crucial to modern astronomers, and lays the groundwork for the fundamental law of of gravity. He calculates the force that holds the planets in their orbits as varying inversely with the square of their distance from the sun.

Newton's genius in mathematics is matched, says Einstein, by his genius in mechanics. Believing that God designed the universe to have a mathematical structure, Newton explains the movements of the tides, the precession of the equinoxes, planetary orbits, and the trajectory of projectiles in one unified set of laws. In the most influential scientific book ever written, the Mathematical Principles of Natural Philosophy (the Principia), he describes terrestrial and celestial mechanics and the three Laws of Motion ( Glass, 2006).

(Dhillon, 2009)

Replica of Newton's 6-inch reflecting telescope of 1672 for the Royal Society


  1. The telescope that Newton built in 1668 had a small curved, or parabolic, mirror that was made from a combination of tin and copper. Of crucial importance was the reflector and eyepiece that Newton added in front of the mirror, so that one could look at the celestial images from the side. Newton's creation looked more like a complicated spyglass than a device for gazing into the heavens, but still the craftsmanship of Newton's optical device is quite evident even from photographs of the antique piece of equipment.
  2. What He Could See

  3. Newton could see Jupiter and several of its moons, along with the different phases of Venus. One must keep in mind that Newton's original mirror was less than an inch and a half in diameter, a very small scope indeed by modern standards. Still, for that day and age the sight of the moons of Jupiter must have been quite an event. For the first 50 years Newtonian telescopes were rather primitive affairs. That all changed in 1721, when John Hadley of Great Britain came up with a slightly more functional and much larger reflecting telescope (Keesing, 2009).


Gravity is the attractive force between all objects in the universe. It is the force that pulls objects to the earth.

Here are some important facts about gravity:

Using scientific language Which translate to...
Gravity is the experience of two particles mutually attracting each other along the line joining them. Imagine yourself deep in space and you are standing next to a brick. When you are running in a marathon, you are running in a particular direction, but gravity has no particular direction, but along the path joining you and that brick.
Spherically symmetric objects interact gravitationally as if their mass were located at their centers. An example of a spherically symmetric object is the Earth.  Earth attracts as if it's mass were located at the centre of Earth.
It is gravity which causes the centripetal acceleration when a satellite moves in a circular orbit. Gravity is what allows a satellite to move in a circular orbit around earth.
For a particular radius of circular orbit there is only one possible speed for a stable satellite orbit. If a satellite wants to orbit 2,000km above Earth, there is only one speed at which it can stably orbit (Shun, 2009).

Isaac Newton


Parkworld Plot

Forces & Motion

click to learn more:

All about forces Module Module questions -
Gravity, stretching & compression Module Module questions Applications
Friction Module Module questions Applications

Balanced & unbalanced forces Module Module questions Applications


Basic Definitions in Physics

The acceleration is the rate of change of the velocity.

The force is the rate of change of momentum.

Inertia is the name for the tendency of an object in motion to remain in motion, or an object at rest to remain at rest, unless acted upon by an outside force.     
Reciprocal actions   
Reciprocal actions correspond but are reversed or inverted; ''To every action there is always an equal and opposite reaction."  
Mass is the amount of matter that a body contains, and a measure of the inertial property of that body, that is, of its resistance to change of motion (Inertia). Mass is different from weight, which is a measure of the attraction of the earth for a given mass (Gravitation). s the rate of change of momentum.

Newton's Laws of Motion
The Newton's 3 laws of motion are: the law of inertia, the law of acceleration and the law of reciprocal actions.
Newton's Laws
1st: Newton's First law states that an object is at rest unless acted on by a force or an object moving at a constant speed will continue to move at that speed unless acted on by a force .

2nd: Newton's Second Law of motion introduces the formula Force equals mass times acceleration.

3rd: The third law follows the law of conservation of momentum used widely in mathematics and states that each action has an equal and opposite reaction (Louviere , 2008).

Isaac Newton

NETS Standards
1. Facilitate and Inspire Student Learning and Creativity
Teachers use their knowledge of subject matter, teaching and learning, and technology to facilitate experiences that advance student learning, creativity, and innovation in both face-to-face and virtual environments. Teachers:
a. promote, support, and model creative and innovative thinking and inventiveness.
b. engage students in exploring real-world issues and solving authentic problems using digital tools and resources.
c. promote student reflection using collaborative tools to reveal and clarify students' conceptual understanding and thinking, planning, and creative processes.

2. Design and Develop Digital-Age Learning Experiences and Assessments
Teachers design, develop, and evaluate authentic learning experiences and assessment incorporating contemporary tools and resources to maximize content learning in context and to develop the knowledge, skills, and attitudes identified in the NETS%u2022S. Teachers:
a. design or adapt relevant learning experiences that incorporate digital tools and resources to promote student learning and creativity.
b. develop technology-enriched learning environments that enable all students to pursue their individual curiosities and become active participants in setting their own educational goals, managing their own learning, and assessing their own progress.
c. customize and personalize learning activities to address students' diverse learning styles, working strategies, and abilities using digital tools and resources.
d. provide students with multiple and varied formative and summative assessments aligned with content and technology standards and use resulting data to inform learning and teaching.
3. Model Digital-Age Work and Learning
Teachers exhibit knowledge, skills, and work processes representative of an innovative professional in a global and digital society. Teachers:
a. demonstrate fluency in technology systems and the transfer of current knowledge to new technologies and situations.

c. communicate relevant information and ideas effectively to students, parents, and peers using a variety of digital-age media and formats.
d. model and facilitate effective use of current and emerging digital tools to locate, analyze, evaluate, and use information resources to support research and learning.
4. Promote and Model Digital Citizenship and Responsibility
Teachers understand local and global societal issues and responsibilities in an evolving digital culture and exhibit legal and ethical behavior in their professional practices. Teachers:
a. advocate, model, and teach safe, legal, and ethical use of digital information and technology, including respect for copyright, intellectual property, and the appropriate documentation of sources.

c. promote and model digital etiquette and responsible social interactions related to the use of technology and information.

National Standards Correlation

As a result of their activities in grades 5-8, all students should develop an understanding
  • Physical Science
    • Position and motion of objects
      • An object's motion can be described by tracing and measuring its position over time. (velocity)
    • Motion and Forces
      • Unbalanced forces will cause changes in the speed or direction of an object's motion. (Acceleration)
      • The motion of an object can be described by its position, direction of motion, and speed.
      • An object that is not being subjected to a force will continue to move at a constant speed and in a straight line. (inertia)


5th grade
Competency Goal 4: : The learner will conduct investigations and use appropriate technologies to build an understanding of forces and motion in technological designs.


4.01 Determine the motion of an object by following and measuring its position over time.
4.02 Evaluate how pushing or pulling forces can change the position and motion of an object.
4.03 Explain how energy is needed to make machines move.
  • Moving air.
  • Gravity.
4.04 Determine that an unbalanced force is needed to move an object or change its direction.
4.05 Determine factors that affect motion including:
  • Force
  • Friction.
  • Inertia.
  • Momentum