Dr. Nefario believes that the effects of the shrink ray will last the longest on objects of
small mass. To test this he exposes a minion, Gru's aircraft and the moon to a blast from the shrink ray Each blast lasts 5 seconds each. He observed that the shrinkage lasted 1 week on the minion, 1 day on Gru's aircraft and 1 hour on the moon.What is the manipulated variable in this experiment?