Two people, one of mass 78 kg and the other of mass 59 kg, sit in a rowboat of mass 88 kg. With the boat initially at rest, the two people, who have been sitting at opposite ends of the boat 2.9 m apart from each other, now exchange seats. How far will the boat move?

The boat will move -0.24 m and the negative sign indicates left direction.

Explanation:

mass of people A = 78 kg

mass of people B = 59 kg

mass of rowboat = 88 kg

Let the displacement of the boat be x

                                        = 2.9 + x

                                        = -2.9 + x

As net external F = 0

                                ∑mx = 0

        88 (x) + 78 (2.9 + x ) + 59 (-2.9 + x) = 0

          88x + 226.2 + 78x - 171.1 + 59x = 0

         225x + 55.1 = 0

                           x = -55.1 / 225

                          x = -0.24

The negative sign indicates left direction.

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop