Lecture 15: Act 1 Solution Both spaceships require the same escape velocity to reach infinity Thus they require the same kinetic energy Both initially have the same potential energy Spaceship 2 already has some kinetic energy due to its rotational motion, so it requires less work (i.e less fuel) Physics 121: Lecture 15, Pg 8Physics 121: Lecture 15, Pg 8 Lecture 15: Act 1 Solution Both spaceships require the same escape velocity to reach infinity. Thus they require the same kinetic energy. Both initially have the same potential energy. Spaceship 2 already has some kinetic energy due to its rotational motion, so it requires less work (i.e. less fuel)