AP Unit 5 - Momentum/Impulse
Thursday 12/17/20
watch this video developing the concept of conservation of momentum
watch this video for homework showing how to use the mass-velocity block (momentum charts) to solve problems
students worked Unit 5H Momentum/Impulse Practice 1 .
went over Unit 5H Momentum/Impulse Practice 1 .
defined momentum as mass times velocity ( or p=mv ) ... p is the variable for momentum ... the units for momentum are kg-m/s
Overview discussion: definition of momentum, 3 1D equations for conservation of momentum (bouncy, sticky, explosion), and several examples using 1D equations.
emphasized that collisions are "inelastic" when kinetic energy is lost...which is pretty much always the case in collisions and explosions (exceptions being in particle physics collisions)
introduced concept of 2D conservation of momentum ... just do conservation of momentum in each direction independently; your final velocity components can then be used to determine the final velocity
discussed a bunch of 1D conservation of momentum problems
Friday 12/18/20
several students took retake...all other students watched linked recording below (from 2nd block)
discussed the momentum impulse relationship
discussed all calculus derivatives and integrals to date
discussed examples of calculating impulse due to constant forces and time dependent forces...note that the impulse is the area captured by the F vs. t graph. For constant forces, one can just find the area geometrically...for time-dependent forces, one must use the integral of the F(t) w.r.t. time over the time interval
Monday - Tuesday 12/21/20 - 12/22/20
discussed types of collisions: inelastic (K_sys,i > K_sys,f); elastic (K_sys,i = K_sys,f); and superelastic (K_sys,i < K_sys,f)
demonstrated a 1D collision simulator
discussed solving elastic collisions in the lab frame with examples (the lab frame is how we have been solving momentum conservation examples...elastic collision solutions involve setting up two conservation equations: conservation of momentum and conservation of energy)
There are three example problems (with solutions given) at the end of the video. You should work through one of them to see that you can get to the correct answer.
Today's Recording (48 minutes)
Wednesday - Thursday 12/23/20 - 12/24/20
watch this video first on the concept of center of mass (3:49)
next, watch this video on the concept of center of mass velocity (8:34)
next, watch this video on solving an inelastic collision in the center of mass frame (4:29)
next, watch this video on solving an elastic collision in the center of mass reference frame (7:01)
discussed solving elastic collisions in center of mass frame with examples (see Today's Recording after watching the above videos in order)
Today's Recording (46:50 ... watch this after watching the videos above)
Saturday - Tuesday 12/26/20 - 1/5/21
work on QAPCM6 2021
due Wed 12/30/20 at 11:59pm*new due date Saturday 1/2/21 at 11:59pm.work on Mastering assignment (large) APCM11 2021
due Sunday 1/3/21 @ 11:59pm*new due date Tuesday, 1/5/21 at 11:59pm.
Monday 1/4/21
livestream
Google Classroom warmup!
we will watch momentum/impulse daily videos from AP Classroom 4.1 Video 1 and 4.1 Video2
discussed finding center of mass of uniform rod using the integral form of finding the position of the center of mass for extended mass objects...chose one end of rod to be origin in the first case and the middle of the rod to be the origin in the second case...got the same result that the center of mass of the rod was at the center of the rod
Tuesday 1/5/21
livestream
Google Classroom warmup!
we will watch momentum/impulse daily videos from AP Classroom 4.1 Video 3 as well as 4.2 (all videos)
work example problems from note packet
No Recording for today
Wednesday1/6/21
Google Classroom warmup!
finish example problems from note packet and work review packet
students worked M problems on Momentum/Impulse
Thursday 1/6/21
no livestream today
No Google Classroom warmup!
students worked M15 and M12
work Mooney review packet
students worked on QAPCM7
students were to work M14 for homework (spend 15 minutes max)
No Recording Today
Friday 1/7/21
livestream
No Google Classroom warmup!
discussed solutions to M15, M12, and M14
worked M13 together
went over solutions to Mooney Review Packet
students worked on QAPCM7
Monday 1/8/21
livestream
No Google Classroom warmup!
finished worked M14 together
went over FR solutions to Mooney Review Packet
discussed center of mass (this time focus is on continuous mass distributions)
discussed several center of mass examples
introduced finding moment of inertia (rotational inertia)
discussed several moment of inertia examples
reviewed the difference between finding the center of mass and the rotational (or moment of) inertia
Today's Recording