The car drove for 2 hours at a speed of 50 km / h, and after that it traveled another 140 km in 2 hours.

The car drove for 2 hours at a speed of 50 km / h, and after that it traveled another 140 km in 2 hours. What is the average speed of the car?

Let the car drove the first section of the path at a speed of v₁ = 50 km / h in time t₁ = 2 hours. Then the distance traveled on this section is found by the formula: S₁ = v₁ ∙ t₁. From the condition of the problem, it is known that on the second section of the path he traveled S₂ = 140 km in t₂ = 2 hours, then for the entire time of movement t = (t₁ + t₂) h the car covered the distance S = (S₁ + S₂) km. The average vehicle speed is determined by the formula:

v = S: t.

We get:

v = (S₁ + S₂): (t₁ + t₂) or v = (v₁ ∙ t₁ + S₂): (t₁ + t₂).

Substitute the values ​​of physical quantities in the calculation formula:

v = (50 km / h ∙ 2 h + 140 km): (2 h + 2 h);

v = 60 km / h.

Answer: The average vehicle speed is 60 km / h.