When a boy travels by bus up a mountain, he gains gravitational potential energy (G.P.E.) as his distance from the Earth's center increases. This increase in G.P.E. can be calculated using the formula P_e = mgh, where 'm' is the total mass of the bus and passengers. Conversely, as the bus descends, the boy loses G.P.E. while his kinetic energy becomes part of the bus's overall energy. The boy's energy changes are directly tied to the bus's motion and elevation. Thus, bus travel does affect the boy's potential energy during the journey.