A basketball player runs a drill in which he runs the length of the 30.0 meter court and back. He does
this three times in 50.0 seconds.
30. m
(Not drawn to scale)
1. The magnitude of the player's total displacement
after running the drill is
(1) 0.0 m
(2) 30.0 m
(3) 60.0 m
(4) 180 m

(1) 0.0 m

Explanation: In physics, displacement is defined as the change in position of a moving object. It is a vector, so has magnitude and direction, determined by a referential create to the system, i.e., the moving object. Mathematically, displacement is calculated by: , in which:

For the basketball player, he runs 30m, 3 times, court and back. Assuming the initial position is 0:

= 0.0

Since displacement is given by, only, the initial and final position and the player started at the initial point and ended at the initial point of the court, displacement is 0.

momentum of soft ball three times less than baskey ball

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.