For the first third of the driving time, the car moved at a speed of 50 km / h, the rest of the time at a speed

For the first third of the driving time, the car moved at a speed of 50 km / h, the rest of the time at a speed of 40 kim / h. What is the average speed of the vehicle along the way?

To find the average speed of the car along the entire path, we write down the formula for the average speed:

uav = sall / tall,

where sall is the message of the path;

t all – all the time.

Let’s write down the value of the first third of the time and the remaining:
tall = t1 + t2 = t / 3 + 2t / 3.

Now the magnitude of the entire distance:
sweight = s1 + s2 = u1t / 3 + 2u2t / 3.

Substitute the path into the equation:
uav = (u1t / 3 + 2u2t / 3) / t.

We will reduce the values of time t and combine the terms into one fraction:
uav = u1t + 2u2t / 3t = u1 + 2u2 / 3.

We substitute all known quantities into the equation:
uav = 50 + 2 * 40/3 = 50 + 80/3 = 76.66 m / s.

Answer: 76.66 m / s.