Which of the following statements is true? Communicable diseases cannot be transmitted by nonliving objects. Sexually transmitted diseases are spread by direct contact with bodily fluids. Gastrointestinal diseases are usually transmitted by infected water droplets in the air. The best prevention against communicable diseases is over-the-counter medication.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change? work power gravitational energy chemical energy

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.

Why do astronauts in the space shuttle weigh less?