Mechanics · Momentum
Chapter 1 · 3
The idea
Impulse and momentum as vectors
How a push changes the motion of a particle moving on a plane: the impulse-momentum principle I = mv − mu in i, j components, the velocity after an impulse, the size of an impulse, the angle the motion is turned through, the kinetic energy gained or lost, impulses with an unknown in them, the momentum triangle, and the equal and opposite impulses when two particles collide.
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Mechanics · Momentum
Impulse and momentum as vectors
How a push changes the motion of a particle moving on a plane: the impulse-momentum principle I = mv − mu in i, j components, the velocity after an impulse, the size of an impulse, the angle the motion is turned through, the kinetic energy gained or lost, impulses with an unknown in them, the momentum triangle, and the equal and opposite impulses when two particles collide.
Why it works
Where does the puck go?
A puck of mass kg slides across smooth, level ice with velocity , where and are perpendicular unit vectors on the ice. A player's stick strikes it, and it shoots off at , straight along . How hard was it hit, and which way?On a flat surface a direction needs two numbers, so momentum is a vector: mass times velocity, component by component. Before the hit the puck's momentum is N s, pointing the way the puck moves.Keep reading — free
The rest of the explanation, plus 5 worked examples you step through move by move.
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