The car, rolling down the mountain, passes the first 120 m in 10 seconds. Rolling down and continuing to move

The car, rolling down the mountain, passes the first 120 m in 10 seconds. Rolling down and continuing to move, it goes to a full stop another 360 m in 1.5 minutes. Determine the average speed of the car for the entire movement.

S1 = 120 m.

t1 = 10 s.

S2 = 360 m.

t2 = 1.5 min = 90 s.

Vav -?

In order to find the average speed of movement Vav, it is necessary to divide the entire path S traversed by the body by the entire time of the entire movement t: Vav = S / t.

The entire path traveled by the car will be the sum: S = S1 + S2.

S = 120 m + 360 m = 480 m.

The travel time of the car will also be the sum: t = t1 + t2.

t = 10 s + 90 s = 100 s.

Let’s substitute the data into the formula: Vav = 480 m / 100 s = 4.8 m / s.

Answer: the average speed of the carriage is Vav = 4.8 m / s.