If Newton’s law “for every action there is an equal an opposite reaction” were true, no action would be possible.
Since the reaction force has to be “equal” and “opposite” it
would cancel action. “Cancel” means cease to exist. Something that doesn’t
exist, can't cause any effect.
The action-reaction law is:
LAW 1
“For every action there is an opposite reaction"
LAW 2
"The result of an action is the momentum of acting body
minus the inertia of the reacting body.”
Newton came to his conclusion because:
LAW 3
“When two forces act on each other, the pressure between
them is equal to their sum. The pressure is split even between them.
EXAMPLES:
1. Collision of balls in vacum.
5 kg 5 kg
A
2 m/s B
Pic.1 Before collision
A B
momentum = 10 kg m/s Inertia = 5 kg
Pic.2
Ball
A gives its momentum to B. Ball B gives its inertia to A. Hence, A becomes inactive and B starts to move at 2
m/s.
A B
inertia=5
kg
momentum= 5 kg * 2m/s
Pic.3
After
the collision there is a switch. Ball B has the momentum and ball A has
inertia.
If for every action there was an equal an
opposite reaction, the momentum of the first ball (10kg*m/s) would have to
be matched by 5kg inertia.
Yet 10 kg*m/s doesn’t equal 5kg.
The
Action A (yellow), meets the Reaction B (blue).
“Action” is first, “reaction” is second. The
inertia of B is matched equally by momentum of A, but inertia isn’t “action”.
According to Newton, inertia isn’t a
“force”, because according to his own definition a force has
"acceleration". Inertia doesn’t have acceleration, but becomes a
force when hit, according to his own definition.
It has
negative acceleration. Inertia is therefore potential force. Since force is
measured only when it acts, inertia should be considered a force.
2. Horse and wagon
The horse diggs his
heels in. That’s why the force of his action
has bigger value than the reaction of
the wagon. The wagon’s “reaction” is just INERTIA,
which is not equal to the action of the horse.
The force on ropes between the horse and the wagon is evenly split. If the horse pulls
with momentum 1000 and the inertia or the wagon takes out 500, then the net
action is 500 for the horse. The pressure on the ropes in between is 1500. It’s splits evenly 750 each way.
Action
is the momentum of the horse and the reaction
is the inertia of the wagon.
They are not equal.
3. A bullet and a
cop
A guy fires a gun at a
cop. The bullet hits a cop and goes through. The bullet hits the wall and falls
down. The cop falls backwards.
If the cop did “an equal an opposite reaction”,
the bullet would never go through.
My law's explanation:
The inertia of the gun, hand and the person holding it is MUCH bigger than the
inertia of the tiny bullet. Hence the bullet has to be propelled by 50% of the
initial force of explosion of gun powder. When the explosion meets the inertia
of the gun it comes SEVERAL FOLDS BACK and ADDS to the 50% of the force that initially
propelled the bullet. Hence, almost all the explosion force goes to the bullet!
This elegantly
explains why though we only feel a jolt when firing a gun, the bullet carries
enormous power!
Then the bullet loses part of its momentum to
the inertia of the flesh. The bullet hits the wall with whatever momentum is
left. The wall’s inertia is too big to be affected by the momentum of the
bullet. The bullet falls down.
4.
Boy jumping from a piece of ice to water.
Since the boy ejects himself from the ice, the momentum of the boy
equals the inertia of the ice.
5. A rocket and
the exhaust.
Since the exhaust comes from the rocket, the force lifting up the rocket will be equal to
the force of the exhaust.
6. Skateboarder
and a ball
A boy throws a ball from a skateboard. The ball
comes from the boy. The boy supplies
the momentum of the ball. Hence, he must experience equal reaction.
PAWEL KOLASA