1. Vectors, Vel and Acc Flashcards
Distance vs displacement
total distance measured regardless of direction; scalar vs final position - initial position (has direction); vector
Vector vs scalar
magnitude + direction vs magnitude
Instantaneous vel vs avg vel
vel at one specific instant (smaller displacment/smaller time interval) vs entire displacement/entire time
Formula for vel and acc
v = displacement/t; a = deltav/deltat
Kinematic eqns
v^2 = v0^2 + 2ax, x = v0t + 1/2at^2, Vf = Vi + at
X and y velocities for projectile motion
x: vox = vx throughout, ax = 0, x displacement = vox*t
y: reg kinematic eqns, ay = -9.8 m/s^2; vy = 0 at the top of the curve
How many meters in angstroms?
10E-10 m
Dot product vs cross product of vectors
Scalar multiplication aka just magnitude, abs(A)abs(B)cos(theta) vs vector multiplication aka both magnitude and direction, abs(A)abs(B)sin(theta)
Watch out for signs when doing kinematic
Gravity is NEG. Establish which way is pos and neg
If given just initial vel for projectile motion, TREAT IT LIKE RESULTANT
You have to break up initial vel into x and y components via kinematics eqns
Where’s the instant vel vector in UCM?
Tangential to circular path
When jumping off a cliff, what are the initial x and y vel?
If person is running and then jumping off —> x vel is always constant, initial y vel is 0 and then use kinematics to find y vel after a certain amount of time
Terminal vel. What acc do you experience during free fall?
Constant vel during free fall. The only acc you experience is gravity (9.8 m/s^2) until it balances out with drag —> terminal vel
For symmetrical trajectories, t1 = t2
Yep. t1 ranges from start to apex, t2 ranges from apex to end
How to interpret vel graphs?
Pos side (ie. Above x axis) —> moving forward; neg side (ie. Below x axis) —> moving backward Higher magnitude —> moving faster; lower magnitude —> moving slower
