Answer:
No it's not true electric grow from Positive terminal to negative terminal
The box is moving in the direction of Eduardo with a force of 300N since he is pulling 300N stronger than Clara.
The echo is heard 2.80 s later, this means this is the time the sound takes to travel to the reflecting object and then back to us. So, during this time, the sound wave has covered the distance L between us and the object twice:

The speed of the sound wave is:

, and since it is moving by uniform motion, we can find the distance covered by the wave using

And we said this corresponds to twice the distance between us and the reflecting object, so:

so, the object is 480 meters away.
<span>So we want to know how did the planets form in the Solar system. So the current most accepted explanation is accretion. First the Sun formed, and what has left was a disk made out of gas and dust which later formed the planets trough attractive gravitational force.</span>