Question

I. igure is a map showing force lines and equal energy contours for a plane in a conservative field. The energy contours have units of J/kg. This means that the amount of energy transferred to/from the field as an object is moved depends on the mass of the object. This also means that the force acting on an object depends on the mass of the object. (a) If an object is moved from a position where its centre of mass is at point A to a position where its centre of mass is at point B, is energy transferred to or retrieved from the field (i.e, does the mover do positive or negative work on the object in moving it from point A to point B)? If the mover does positive work, then energy is being transferred to the field. (b) How much energy is transferred to the field if an object that has a mass of I kg is moved from a position where its centre of mass is at point A to a position where its centre of mass is at point B? (c) How much energy is transferred to the field if a 1 kg object is moved from a position where its centre of mass is at point D to a position where its centre of mass is at point A? kg Jkg o kg Figure 1: Conservative Force Field with Energy contours in steps of J/kg

Answer 1

Mover does a negative work. Hence, the energy is retrieved from field. Energy transfer will be negative to field. Let energy per kg for each box be x J/kg From A to B rightarrow Energy transferred = -x times 6 times 1 Energy transferred = -6x Joules Since, it's a conservative force, work done will be independent of path. Energy transferred = 6x Joules.