On a safari, you are spear fishing while wading in a river. you observe a fish gliding by you. if your line of sight to the fish is 60.0° below the horizontal in air, and assuming the spear follows a straight line path through the air and water after it is released, determine the angle below the horizontal that you should aim your spear gun in order to catch dinner. assume the spear gun barrel is 2.00 m above the water surface, the fish is 1.70 m below the surface, and the spear travels in a straight line all the way to the fish ebook

increases it

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.