Question

Think About 29.3 Victoria is standing on a boat, during a perfectly calm day. Initially, both Victoria and the boat are not moving. Then Victoria walks from one end of the boat to the other. Take the initial time to be before she walks and the final time at some point while she is still walking. (a) Draw a Momentum Chart for this situation. Does the boat move, and if so, in which direction

Answer 1

a) The boat will probably have to turn on its own center of gravity because Victoria generates a torque force with its weight while moving along it, however, the boat will not move because there is no external force that act on him. The boat on its own site will remain static.

(b) If it is required to observe the speed of the two bodies, the most convenient is to use the magnitude of the Momentum. It should be noted that both moments are preserved as seen in (a) and it is also necessary to understand that the two will be of opposite signs, that is, the sum of all the moments will be zero. Therefore, comparing the magnitude of the momentum of the ship and that of Victoria, we get

`m_vV_v = m_bV_b \Rightarrow \frac {V_b} {V_v} = \frac {M_v} {M_b}`

The Boat will always tend to have a speed -small- higher than Victoria's, this because its mass will always be greater.