Jackson and Pember are standing at different distances from a cliff. If Jackson hears his echo in 6 thousandths of a second and Pember hears his echo in .6 seconds, who is closer to the cliff?

The correct answer is that Jackson is closer to the cliff because the time it takes for an echo to return is directly related to the distance from the source of the sound to the reflecting surface and back. When Jackson hears his echo in 6 thousandths of a second, this indicates a shorter distance to the cliff compared to Pember, who hears his echo in .6 seconds.

The time it takes for sound to travel to the cliff and back is a key factor in determining distance. Since sound travels at a constant speed (approximately 343 meters per second in air at room temperature), a shorter time for an echo means that the source of the sound (in this case, Jackson) is closer to the reflecting surface (the cliff). The fact that Pember’s time is significantly longer suggests he is farther away.

In summary, the shorter echo time attributed to Jackson confirms that he is closer to the cliff than Pember is.