NEWTON’S 3 LAWS OF MOTION 12.2 & 12.3

3 SCIENTISTS HAVE CONTRIBUTED TO OUR UNDERSTANDING OF FORCE & MOTION ARISTOTLE: AN ANCIENT GREEK SCIENTIST AND PHILOSOPHER (384 B.C. – 322 B.C.) USED OBSERVATION AND LOGICAL REASONING HE INCORRECTLY THOUGHT THAT FORCE WAS NEEDED TO KEEP AN OBJECT MOVING AT A CONSTANT SPEED. GALILEO: ITALIAN SCIENTIST ( ) EXPERIMENTED FOUND THAT WITHOUT FRICTION OBJECTS WOULD CONTINUE ON INDEFINITELY. SIR ISAAC NEWTON:

SIR ISAAC NEWTON BUILD UPON WORK OF SCIENTIST SUCH AS GALILEO. PUBLISHED HIS SCIENTIFIC FINDINGS IN A BOOK CALLED PRINCIPIA.

SIR ISAAC NEWTON HE STATED THAT EVERY MOTION YOU OBSERVE OR EXPERIENCE IS RELATED TO FORCE. SIR ISAAC NEWTON DESCRIBED THE RELATIONSHIP BETWEEN MOTION AND FORCE IN THREE LAWS THAT WE NOW CALL NEWTON’S LAWS OF MOTION.

NEWTON’S FIRST LAW OF MOTION

NEWTON’S FIRST LAW AN OBJECT AT REST REMAINS AT REST AND AN OBJECT IN MOTION REMAINS IN MOTION UNLESS IT EXPERIENCES AN UNBALANCED FORCE

NEWTON’S FIRST LAW HAVE YOU EVER NOTICED THAT WHEN YOUR CAR STOPS YOUR BODY TRIES TO CONTINUE FORWARD? THAT IS AN EXAMPLE OF NEWTON’S FIRST LAW

NEWTON’S FIRST LAW INTERTIA IS THE TENDENCY OF AN OBJECT AT REST TO REMAIN AT REST OR, IF MOVING, TO CONTINUE MOVING WITH A CONSTANT VELOCITY. ALL OBJECTS HAVE INERTIA.

NEWTON’S SECOND LAW OF MOTION

NEWTON’S SECOND LAW FORCE = MASS X ACCELERATION F = FORCE (N) M = MASS (kg or g) A = ACCELERATION (kg/h 2 or m/s 2 )

NEWTON’S SECOND LAW WHAT IS THE DIFFERENCE WHEN YOU PUSH AN EMPTY SHOPPING CART AND A FULL SHOPPING CART? IF THE FORCE USED TO PUSH THEM IS THE SAME: WHICH CART HAS THE FASTER ACCELERATION?

NEWTON’S SECOND LAW ZOOKEEPERS LIFT A STRETCHER THAT HOLDS A SEDATED LION. THE TOTAL MASS OF THE LION AND STRETCHER IS 175 KG, AND THE LION’S UPWARD ACCELERATION IS M/S 2. WHAT IS THE UNBALANCED FORCE NECESSARY TO PRODUCE THIS ACCELERATION OF THE LION AND STRETCHER? F = M = A =

FREE FALL AN OBJECT IS CONSIDERED TO BE IN FREE- FALL WHEN THE ONLY FORCE ACTING UPON IT IS GRAVITY. FREE-FALL ACCELERATION IS ALWAYS WHAT?

FREE FALL SINCE THE ACCELERATION IS CONSTANT, TWO OBJECTS WITH DIFFERENT MASSES WILL HIT THE GROUND AT THE SAME TIME (DISREGARDING AIR RESISTANCE) FOR EXAMPLE, IF YOU DROPPED A 1.5 KG BOOK AND A 15 KG ROCK FROM THE SAME HEIGHT THEY WILL HIT THE GROUND AT THE SAME TIME.

WEIGHT WEIGHT IS DIFFERENT FROM MASS BECAUSE WEIGHT IS THE FORCE OF AN OBJECT DUE TO GRAVITY. YOUR MASS IS THE SAME ON EARTH AS IT IS ON THE MOON. YOUR WEIGHT IS DIFFERENT ON EARTH AND THE MOON.

WEIGHT WEIGHT = MASS X GRAVITY W = WEIGHT (N) M = MASS (KG)

NEWTON’S THIRD LAW

FOR EVERY ACTION FORCE, THERE IS AN EQUAL AND OPPOSITE REACTION FORCE.

NEWTON’S THIRD LAW AN EXAMPLE OF NEWTON’S THIRD LAW IS WHEN YOU KICK A SOCCER BALL. WHAT HAPPENS TO THE BALL WHEN YOU KICK IT? WHAT HAPPENS TO YOUR FOOT WHEN YOU KICK THE BALL?

NEWTON’S THIRD LAW ROCKETS ARE ANOTHER EXAMPLE OF NEWTON’S THIRD LAW.