force

• •Force is a push and pull exerted by one body to another body. The effect of which is to tend to change or change the state of motion of the body on which it act.
• •Gravitational force- the force of attraction between object by virtue of their masses
• •Electromagnetic force- either an attractive force and repulsive force between charged bodies
• •Strong nuclear force- holds the constituent of the nucleus of an atom together.
• •Weak nuclear force- play a role in the radioactive decay of some nuclei.
• Non fundamental forces-•Other than gravity, ordinary forces like pushes and pulls, friction and other forces considered in this chapter as non fundamental forces.
• Newton’s Contributions
• Newton’s First Law-An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force.(law of inertia)
• •MASS is the measure of the amount of matter  in an object.

  •It is measured in Kilograms
• •INERTIA is a property of an object that describes how much it wil resist change to the motion of the object••more mass means more inertia.
• Friction- The force of friction is the force that opposes the motion of an object.
• 2nd law-The net force of an object is equal to the product of its mass and acceleration, or F=ma.
• •Force = Mass x Acceleration•Force is measured in Newtons

  ACCELERATION of GRAVITY(Earth) = 9.8 m/s2

   Weight (force) = mass x gravity (Earth)

  Moon's gravity is 1/6 of the earth's.
• 3rd law( interaction)-For every action there is an equal and opposite reaction.