Newton’s Laws of Motion

Newton’s First Law  The Law of Inertia  Inertia- the tendency of an object to resist a change in motion.  An object at rest will remain at rest, and an object moving at a constant velocity will continue moving at a constant velocity, unless it is acted upon by an outside force.

Newton’s First Law  On Earth, gravity and friction are unbalanced forces that often change an object’s motion.  The greater the mass of an object is, the greater its inertia, and the greater the force required to change its motion.  Example: The tennis ball thrown in the air will continue until the force of gravity and friction will eventually stop the ball.

Newton’s Second Law  The Law of Constant Acceleration  Acceleration depends on the object’s mass & on the net force acting on the object.  Acceleration= Net Force/ Mass  Acceleration is measured in meter per second per second ( m/s²)

Newton’s Second Law  To increase acceleration either decrease the mass or increase the force.  Example: Rolling a golf ball and a bowling ball using the same force, the golf ball would have a greater rate of acceleration.

Newton’s Third Law  If one object exerts a force on another object, then the second object exert a force of equal strength in the opposite direction on the first object.  For every action there is an equal but opposite reaction.  Example: When you hit a nail with a hammer, the hammer exerts a force on the nail. The nail exerts a force on the hammer, causing the motion of the hammer to stop.

Newton’s Third Law  Momentum means “a quantity of motion”  Momentum= Mass x Velocity  The more momentum a moving has, the harder it is to stop.  The conservation of momentum means when objects collide momentum is not lost but transferred from one object to another.