The world is wide, and I will not waste my life in friction when it could be turned into momentum.

Frances E. Willard

A MATHEMATICL DEFINITION OF MOMENTUM IS

p = m x v OR

MOMENTUM = MASS X VELOCITY

THINK OF MOMENTUM AS “MASS IN MOTION”.

THE UNITS OF MOMENTUM WILL BE kg m/s

THE MOMENTUM OF AN OBJECT AT REST (0 m/s) IS ZERO.

A HALFBACK (60 kg), A TIGHT END (90 kg), AND A LINEMAN (120 kg) ARE RUNNING DOWN THE FIELD. THE HALFBACK IT RUNNING AT 9 m/s, THE TIGHT END IS RUNNING AT 6 m/s, AND THE LINEMAN IS RUNNING AT 3 m/s. WHICH HAS THE GREATEST MOMENTUM.

Phb = 60 x 9 = 540 kg m/s

Pte = 90 x 6 = 540 kg m/s

Plm = 120 x 3 = 360 kg m/s

THE EQUATION FOR FORCE IS GIVEN AS

F = m x a

WHERE F = FORCE, m = MASS, a = acceleration

a = Dv/Dt SO F = m x Dv/Dt

MULTIPLYING BOTH SIDES OF THE EQUATION BY Dt GIVES

F X Dt = m x Dvimpulse

Change in momentum

IN A COLLISION, AN OBJECT EXPERIENCES A FORCE FOR A GIVEN AMOUNT OF TIME THAT RESULTS IN ITS MASS UNDERGOING A CHANGE IN VELOCITY (I.E., THAT RESULTS IN A MOMENTUM CHANGE).

AN OBJECT WITH 100 UNITS OF MOMENTUM MUST EXPERIENCE 100 UNITS OF IMPULSE IN ORDER TO BE BROUGHT TO A STOP. ANY COMBINATION OF FORCE AND TIME COULD BE USED TO PRODUCE THE 100 UNITS OF IMPULSE NECESSARY TO STOP AN OBJECT WITH 100 UNITS OF MOMENTUM.

Combinations of Force and Time Required to Produce 100 units of Impulse

Force Time Impulse

100 1 100

50 2 100

25 4 100

10 10 100

4 25 100

2 50 100

1 100 100

0.1 1000 100

REAL WORLD APPLICATIONS:

AIR BAGS

NYLON CLIMBING ROPES

BUNGEE JUMPING

BOXING

http://www.wimp.com/momentumtale/

A TALE OF MOMENTUM AND INERTIA

The idea about inertia applies to movable things like balls and bats and cars and planes. Anything that is at rest stays at rest unless something else gives it a push. Then it is a moving body. And when in motion, it tends to keep moving in a straight line unless some force pushes or pulls to stop it or make it turn.So the idea about inertia is simply that something tends to keep on doing whatever it is doing.When something is moving it has momentum. The heavier it is and the faster it is moving, the harder it is to stop. So momentum is a kind of measurement of how hard it is to stop something in motion.