Distance
force
vector addition
decreases
projectile motion displacement
mass
increases
vector subtraction
linear motion time
speed
positive
equally
vector multiplication velocity
gravity
negative
unequally
centripetal motion
short answers:
20. which of the following variables are vectors: distance, speed, displacement, acceleration, or velocity?
21. every winter, greg flies hom to chicago (644 miles from little rock). it takes 2 hours. what is greg’s velocity?
22. a race car travels around a curve at a constant speed. is the race car accelerating? why or why not?

Consider each of the electric- and magnetic-field orientations given next. in each case, what is the direction of propagation of the wave? a)\vec ein the +xdirection,\vec bin the +ydirection. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction b)\vec ein the -y direction,\vec bin the +x choose+ x direction- x direction+ y direction- y direction+ z direction- z direction c)\vec ein the +z direction,\vec bin the -x direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction d)\vec ein the +y direction,\vec bin the -z direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction