The car was on the way for 4 hours and moved at an average speed Vav = 40 km / h.

The car was on the way for 4 hours and moved at an average speed Vav = 40 km / h. During the first hour of movement, the average speed of the car was equal to V1 = 55 km / h. Determine the average speed of the car for the remaining three hours of movement.

Average speed is the ratio of the total distance traveled to the total travel time. Let’s find the total distance covered by the car:
40 * 4 = 160 km;

Let’s find the distance for the first hour of movement:
55 * 1 = 55 km;

Let’s find the distance covered for the remaining 3 hours of movement:
160 – 55 = 105 km;

Let’s find the average speed of the car for the remaining 3 hours of movement:
105/3 = 35 km / h;

Answer: the average speed for the remaining 3 hours of movement is 35 km / h.