A pendulum swings back and forth once per second. The pendulum is shortened by removing half of the string. The new frequency is 1.4 Hz (Hz=1/sec). How often will the pendulum swing back and forth in a minute?

This section of the U.S. Army's SIFT (Selection Instrument for Flight Training) exam tests your knowledge of basic physics, electrical, and mechanical theories.

Mechanical Comprehension questions focus on topics such as force, friction, current, fluid, pressure, pulleys, gears, screws, engines, and other machine operations.  You must familiarize yourself with physics, basic electronics, and mechanics concepts.