Distinguish between instantaneous speed and average speed. a man drives a car a distance of 200km at an average speed of 44kmh¹,what must be it's average speed for the next 220km, if the car is to cover the total distance in 9 hours?

49.32km/h

Explanation:

Given a man drives a car a distance of 200km at an average speed of 44km/h

We know that

initially

time=4.54 hours

Now Given the total trip should be completed in 9 hours

the time taken to complete the second part of the trip is 9-4.54=4.46 hours

Given the distance travelled in the second half is 220km

We know that  

average speed = 49.32 km/h.

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.