Download - Plan for Today (AP Physics 1) Turn in 7.1 Homework Discuss Review Questions on Final Wrap Up Labs
Plan for Today (AP Physics 1)
• Turn in 7.1 Homework• Discuss Review• Questions on Final• Wrap Up Labs
Final Review Information and Review
What to expect
• Around 15 problems (+/- 2)• That means 6 minutes a problem – this is about the same pace as
your tests• Don’t spend too long on one or two problems – you won’t finish
Chapter 2 – Constant Velocity Problem• Constant velocity problem – v = x/t• How this might look is a “How long did somebody have to wait”
problem• Or a highway drive and what mile marker type problem
Chapter 2 – Constant Acceleration Problem (Linear Motion)• Something like a brick sliding across the floor• You will use one of the four constant acceleration equations• Know three things, solve for the forth• Be sure to list givens so you don’t flip flop final and initial velocity and
keep everything straight
Chapter 2 – Analysis of Motion Using a Graph• Slope of x vs t gives you v. Slope of v vs t gives you a• Area under a vs t gives you v. Area under v gives you x.• Expect to have to calculate and/or sketch this
Chapter 2 – Free fall in one dimension• Same as constant acceleration except we know the acceleration
automatically (might not be given it)• G = 9.8 m/s/s• List givens, use one of the four equations of constant acceleration• DO NOT switch between those equations and v = x/t
Chapter 3 – Horizontally launched projectile• V = Vx• Vyi = 0• Make x/y chart• Remember, two things on x side to solve, three on y• Time is the only thing that crosses over• On x side, use v = x/t• On y side use equations of constant acceleration
X/Y Charts
Chapter 3 – Projectile Motion
• X / Y chart• You need to break the initial velocity into x and y components using
trig (sin, cos)• Don’t be tempted to make pretty triangles to show the motion (see
next page)• Y side = equations of constant acceleration• X side = v = x/t (DO NOT USE EQUATIONS OF CONSTANT
ACCELERATION)• Range equation – or not
Projectile Motion Diagram
Chapter 3 – Vector Graphical and Algebraic Addition• Graphically• Set a scale• Pick a spot around the middle of the paper• Draw to scale carefully measuring lines and angles• Be sure to measure the right direction (NE vs. EN for ex)• Draw the resultant from the start of the 1st vector to the end of the
last• Measure its length and angle
Ch 3 – Algebraic Vector Addition
• Break each vector into x and y components (using sin and cos)• When in doubt, sketch it out to determine if you need sin or cos• Determine if vectors are + or – • N, E = +, S, W = -
• Add all x components together and all y components together• Use Pythagorean theorem to get the resultant vector• Use tan (y/x) to get the angle
Chapter 3 – Relative Velocity (River Crossing)• Constant velocity in two directions• Use v = x/t in both directions• NO equations of constant acceleration• Draw the situation out• Be sure to pay attention to what the question is asking – how far
downstream, velocity relative to the shore, etc• Remember similar triangles if needed
Relative velocity picture
Chapter 4
Chapter 4 – description of a demo using Newtons laws• Given a situation, be able to describe how each of Newton’s laws tie
in• Newton’s 1st law – • An object at rest stays at rest and an object in motion stays in motion unless
an outside force acts on them
• Newton’s 2nd law• F = ma
• Newton’s 3rd law• For every action force there is an equal and opposite reaction force
Chapter 4 – Simple Acceleration Problems• Fnet = ma• Draw a FBD• Solve for Fnet (be careful with directions, breaking forces into x y
components)• Divide by m to get mass
Chapter 4 – Constant velocity and static problems• For both (object at rest or moving at a constant speed)• A = 0 so Fnet = 0• Using that piece of information, you can solve for unknown forces in
x/y direction (or parallel and perpendicular if down a ramp)
Chapter 4 – Net force and accelerated motion down a ramp or force at an angle• Remember for ramps• Break forces into parallel and perpendicular • Add all forces in parallel direction and all forces in perpendicular• Fg = mg• Fg parallel = mgsin angle (this is a flip)• Fg perpendicular = mg cos• Careful with FBD to see this• Fn = Fg perpendicular (NOT JUST Fg)
• Acceleration will be parallel to the ramp (Fnet parallel to ramp)• Fnet = ma to solve
Chapter 5 – Application of Work
• Work = F * d * cos theta• Think about when to include cos of the angle• Possibility: Find Fnet in the same direction as the motion (distance)
and then you NEVER have to worry about the angle • Be able to find work of various forces acting on an object• Be sure to find the component of force along the direction of the
motion
Chapter 5 – Work Kinetic Energy Theorem• Work = Change in KE• In general, Work = Change in Energy• If you know some components, you can solve for others• F * x = ½ mvf^2 – ½ mvi^2• Be careful with plugging in values to solve
Chapter 5 – Conservation of Mechanical Energy• MEi = MEf• PEei + PEgi + KEi = PEef + PEgf + KEf• Cancel out what you can• Solve for unknowns• Don’t go “cancelling mass” happy• If you have a mass, plug it in, especially if you have a spring• Be sure to work and be careful simplifying and solving for your answer
Chapter 5 – Nonconservative Work
• Wnc = MEf – MEi• Figure out what initial mechanical energy you have and what final ME
you have• DO NOT cancel mass here because Wnc doesn’t have mass in it
(probably)• Be able to solve for F or d (W = F * d so once you know Wnc. . . )• If you solve it this way, Wnc will be negative
• Can also set up Mei = Mef + Wnc – will be positive this way
Chapter 5 - Power
• P = W/t• Power = Change in ME/t• Figure out what type of ME is changing for this problem• Also P = F * v for constant velocity ONLY• Note: if no work is being done, no power
Chapter 6
Chapter 6 – Application of F * t = m * v• Plug in to equation and be able to solve for unknowns• Remember it’s change in v, so be able to solve for initial or final given
the others• Also be able to recognize what the problem is asking for (Impulse?
Force?)
• Written response• Like the egg falling - be able to explain why a phenomenon occurs
and how it relates to impulse
Chapter 6 – Conservation of Momentum in Simple Systems• Pi = Pf• M1V1i + M2V2i = M1V1f + M2V2f• Be careful to include directions if needed• Be sure to pay attention to which mass goes with which velocity or if
the masses are combined at some point
Chapter 6 – Ballistic Pendulum (and Complex Collisions in General)• Stages (most general)• Movement before (Conservation of ME)• Collision (Conservation of Momentum)• Movement after (Conservation of ME)
Ch 6 – Ballistic Pendulum
• Stages• Collision – Conservation of Momentum• M1v1i + m2v2i = vf(m1 + m2)
• Pendulum (and bullet) rise into the air• Conservation of energy• Mei = Mef• Kei = Pegf• Masses are the same here• ½ m v^2 = mgh
Elastic Collision in One Dimension
• Momentum is conserved• M1v1i + m2v2i = m1v1f + m2v2f• Pay attention to directions
• Kinetic Energy is also conserved• Use this equation:• V1i – v2i = -(v1f – v2f) to solve
Chapter 7
Chapter 7 – Constant Angular Acceleration• Our constant acceleration equations transformed• Same idea – ID variables and solve • Should be pretty straightforward
Chapter 7 – Simple Circular Motion Problems• ID variables and plug in• Fairly straightforward
Chapter 7 – Centripetal Motion
• Straight forward• Solving for tangential velocity, centripetal acceleration or force• Plug in values