In which one of the following locations can a person hear the echo of a sound?
*a. *less than 16.6 meters in front of the reflecting surface
*b. *at least 33.2 meters behind the reflecting surface
*c. *less than 33.2 meters behind the reflecting surface
*d. *at least 16.6 meters in front of the reflecting surface

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.

How are positive ions different from neutral atoms

Wo small variable-thrust jets are actuated to keep the spacecraft angular velocity about the z-axis constant at ? 0 = 1.16 rad/s as the two telescoping booms are extended from r1 = 1.18 m to r2 = 4.69 m at a constant rate over a period of 124 seconds. the small 19-kg experiment modules at the ends of the booms may be treated as particles, and the mass of the rigid booms is negligible. determine the necessary thrust t for each jet as a function of time where t = 0 is the time when the telescoping action is begun. after you have the general expression for t, answer the questions. show work.