•Force is the pull of gravity exerted on an object
or an object’s thrust of energy against friction.
•You apply a force on a machine; the machine,
in turn, transmits a force to the load.
A tension force is a pulling force exerted by an
object when it is stretched, such as a rubber
•A compression force is a pushing force exerted
by a material when it is squeezed or
• The size of the compression force exerted by a
material is equal to the size of the force that
compresses the material.
Sir Isaac Newton is regarded to be one of the most influential
scientists of all time. He studied physics and created the three
laws of motion. This PowerPoint will tell you more about Sir
Born: December 25, 1642, Woolsthorpe, United Kingdom
Died: March 20, 1727, Kensington, United Kingdom
Full name: Sir Isaac Newton
Education: Trinity College, Cambridge (1667–1668).
Parents: Isaac Newton Sr., Hannah Ayscough
Isaac Newton studied in Cambridge and he was a professor
there from 1669 to 1701. His most important discoveries
were made during 1664 to 1666 when the university closed
and he retired from his job and returned to his hometown.
From there he discovered the law of gravity from the apple
story. He also discovered that white light is made of all the
colours of the rainbow. These things have made him able to
make contributions to mathematics, astronomy and physics.
• Isaac was born in England, and was a physicist, astronomer,
mathematician, philosopher, alchemist and theologian.
• In 1687, Newton published Philosophae Naturalis Principia
Mathematica, which is one of the most important books in the history
of science. In it Newton describes gravitation and the three laws of
• Newton’s law of gravitation describes the gravitational attraction with
bodies with mass..
• Newton moved to London in 1696 and took up a job as the Warden of
the Royal Mint.
• Newton is known to have said that his work on the theory of
gravitation was made by watching an apple fall from a tree. This story
is still popular today.
• The ball does
not travel in a
because of the
force of gravity
acting on it.
Friction is a force that opposes the movement
between two surfaces in contact.
• A book pushed across a table slows down
because of friction.
• Friction is an unbalanced force acting on the
book to slow it down.