Are Car Travels certain distance with a speed of 50 kilometre per hour and returns with a speed of 40 kilometre per hour what is the average speed for the whole journey Best answer branlist and NO LINKS​

The average speed for the whole journey is 44. kilometers per hour

Explanation:

The average speed with which the car travels the distance, v₁ = 50 kilometer per hour

The average speed with which the car returns, v₂ = 40 kilometer per hour

Average speed, v = (Total distance, d)/(Total time, t)

Let 'd' represent the distance travelled, we have;

The time it takes the car to travel to the distance = d/50 hours

The time it takes the car to return = d/40 hours

The total time = (d/50 hours + d/40 hours) = d·(40 + 50)/(40 × 50) hours= 9·d/200 hours

The total distance = d kilometers+ d kilometers = 2·d kilometers

The average speed for the whole journey, v = 2·d kilometers/(9·d/200 hours) = 400/9 kilometers per hours = 44. kilometer/hour.

1 a

2 b

3 b

4 d

5 d

6 d

explanation:

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.