***worth 100 points*** . . . . sally walks 10 meters forward and then 5 meters backwards. which statement most accurate describes the magnitude of her displacement and distance travelled? a) sally's displacement is 5m less than her distance travelled. b) sally's displacement is 10m less than her distance travelled. c) sally's displacement is 5m greater than her distance travelled. d) sally's displacement is 10m greater than her distance travelled. free fall is a situation in which the only force acting upon an object is gravity. why do all objects in free fall have the same acceleration? a) their masses are always the same b) acceleration due to gravity is always the same c) the distance between two objects is always the same d) the gravitational force between two objects are always the same

Displacement is a vector which means it has direction and can have positive or negative values. Distance is a scalar which means it has no direction and positive only.

Sally walks 10 meters forward and then 5 meters backwards. Forward is postive and backward is negative. Her displacement is +10+(-5) = +5m and her distance is 10+5=15m. So the answer is B) Sally's displacement is 10m less than her distance travelled.

Newton 2nd law states that force = ma.  In free fall, the only force is gravity force which is equal to mg where g is gravitational acceleration.  The acceleration is always the same because B) acceleration due to gravity is always the same.

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.