Transcript Newton`s Laws of Motion

Sir Isaac Newton
1642-1727
Newton’s Laws of Motion
Newton’s 1st Law of Motion
-An object at rest, will remain at rest,
unless acted upon by an unbalanced
force.
-An object in motion, will remain in
motion, in a straight line, at constant
speed, unless acted upon by an
unbalanced force.
INERTIA
tendency of an object to resist motion
Newton’s Laws of Motion
Newton’s 2nd Law of Motion
-A force acting on an object will cause it to
accelerate in the direction of the applied force
-Objects with greater mass require more force to
accelerate them
-Objects with greater acceleration exert more force
Force = mass x acceleration
F = ma
units: kg m/s/s
Newton’s Law of Motion
Newton’s 3rd Law of Motion
-For every action, there is an equal and
opposite reaction force. Force occurs in
pairs
ACTION = REACTION
p = mv
Forces
FORCE- push, or pull, of one object on
another object
- a force acting on an object causes the
object to ACCELERATE
FORCE = MASS X ACCELERATION
F = ma
Units: kg (m/s2) = 1 NEWTON
Instrument: Spring Scale
CONTACT FORCES
-Forces resulting from contact between two objects
Ex. Friction -the force that opposes motion between
two contacting surfaces.
air resistance- the force that opposes motion
between an object and the air
FIELD FORCES
-Forces existing between two objects in the absence
of contact
Ex. Gravity-the force that every object in the
universe exerts on every other object in
the universe.
Electromagnetic –force created by
electricity/magnetism
BALANCED FORCE -equal/opposite forces
-no motion is produced
500 N
500 N
UNBALANCED FORCE–unequal/opposite forces
-motion is produced
1000 N
500 N
NET FORCE - Fnet , total sum of all forces acting on an
object
S F = sigma F = sum of forces in a particular
direction
S Fx = 500N -500N = 0N
S Fx = 1000N – 500N = 500N