M1 Mechanics
Momentum
Momentum is the quantity of
motion, and is a product of the mass and velocity of an object.
Momentum = mass x velocity
Where p is momentum in kgms-1, m is mass in kg
and v is velocity in ms-1
Momentum and velocity are vectors because they have both a
magnitude (size) and a direction. Mass
is a scalar quantity because it has no direction.
Conservation of momentum
Imagine
this: we’re on the rink at an ice hockey game.
There’s no friction worth worrying about. Two players skate towards each other and
collide. One bloke weighs a lot more
than the other, but the lighter guy skates much faster.
Newton
)
Superstar English scientist and mathematician Sir Isaac Newton
discovered three rules which describe motion.
So famous did he become, Cambridge University
named a whole building after him. The M1 module is entirely based on so-called
Newtonian mechanics invented by the man himself. Check out those curls - he may have
kick-started modern physics but he sure didn’t have a clue about haircuts! Looks like Justin Hawkins from The Darkness.
Newton
I. Every object in a state of uniform motion tends to remain
in that state of motion unless an external force is applied to it.
This is often termed simply the "Law of Inertia".
Newton
II. The relationship between an object's mass m, its
acceleration a, and the applied
force F is F = ma.
Acceleration and force
are vectors (as indicated by their symbols being displayed in bold font); in
this law the direction of the force vector is the same as the direction of the
acceleration vector.
Newton
III. For every action there is an equal and opposite reaction.
Imagine what happens
if you step off a boat onto the bank of a lake: as you move in the direction of
the shore (towards it), the boat tends to move in the opposite direction (away
from the shore). If you do this, you
might fall in the water! But imagining
it helps you remember that