Momentum 04

OPENING QUESTION: We need a bit of practice in writing analytically. To wit: Use claims/evidence/reasoning to analyze this data:

What about THIS?

FORMULAE OBJECTUS:

  • p = mv
  • J = F∆t = ∆mv = ∆p
  • ∫Fdt = ∆p
  • ∑F = dp/dt
  • m1v1i + m2v2i = m1v1f + m2v2f

WORDS O' THE DAY:

  1. momentum (p)

    impulse (J): "A measure of the degree to which an external force changes the particle's momentum". Note: Our book uses the term (I) to denote impulse, but that's not standard since (I) usually stands for the moment of Inertia (as we'll see in the next chapter). The AP Equation Sheet uses J to denote impulse.

    conservation of linear momentum

  2. Newton's 2nd Revised: ∑F = dP/dt (the sum of the forces acting on a particle (or system) is equal to the change in momentum with respect to the time in which those forces acted)
  3. elastic collisions: Objects collide and then separate -- kinetic energy and momentum are BOTH conserved
  4. perfectly inelastic collisions: Objects collide and then stick together -- momentum IS conserved but kinetic energy is not
  5. inelastic collisions: Objects collide but do not stick together -- momentum IS conserved but kinetic energy is not

═══════════════════════════

WORK O' THE DAY:

Let's take a gander

From Yesterday:

BOO! (and no, not like in the Halloween Boo!, more like poor performance boo!) Apparently nobody took a gander at our labs over the weekend.

To wit... I have gone ahead an purchased connectors that may (or may not) allow us to string cables together.

I've also purchased a wireless accelerometer and a wireless motion detector. Those may (or may not) be approved and arrive by next week (then again they may not).

I spoke with the vendor and we may be able to jury rig our own connections using speaker wire I have at home (by "we", I, of course, mean *you*)

═══════════════════════════

<<<<<RANT begins>>>>>

<<<<<RANT ends>>>>>

═══════════════════════════

Divide and conquer section 9.6:

  • Please have one person peruse and be prepared to elaborate articulately on the work leading up to equation 9.31 (algebra)

  • Please have one person peruse and be prepared to elaborate articulately on the work leading up to equation 9.34 (calc)

  • Please come prepared with 3cselected homework problems that you have completed that relate to your section.

EVERYONE:

Please review example 9.11: The Center of Mass of a Rod. Their approach (a long thin rod with linear density λ <ofsomesort> relating to <something> will absolutely be used on the test either in mechanics or EM

If time permits, take a look at part B.