the power question was the person running up the slipway or whatever it was, directly up to the top, because power is calculated by the formula energy over time or in this case, work done over time, and this means that the smallest possible time would give the biggest power, so i chose the person who went straight up the slope.
the magnetic field question if it was question 17 with the magnet and 4 compasses, was c which was the compass on the right of the magnet as it was the only compass that actually lay on the magnetic field.
cheers =) and im pretty sure boundary will be 35 or less, it was a pretty tough paper...