The body went 450 meters within 30 seconds of starting the movement. In what time did the first 50 meters go?

3.33 seconds.

Explanation:

We can find the speed of the body using the formula,

Speed = Distance traveled in meters / time taken in seconds

= 450 m / 30 seconds

= 15 m/s

So per second the distance traveled by the body is 15 m.

So time needed to travel 50 m can be found as,

time = distance/speed

= 50 m / 15 m / s

= 3.33 s