It extracts energy from food for the cell.
We will put the number of trips in the first column, the miles driven in the second column and gallons of fuel used in the third column.
8 7,680 1,010
7 9,940 1,330
12 14,640 1,790
12 13,920 2,050
Momentum is (mass) times (speed), so nothing that is at rest has any momentum. If the battleship is at rest, then a mosquito in flight, a leaf falling from a tree, and your speedy baseball each have more momentum than the ship has.