waves are generated when a source of energy forces matter in a medium (solid, liquid, or gas) to vibrate. How does the study of the Earth's layers relate to the study of waves

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

Which of the following is not a part of the respiratory system? a. pharynx b. trachea c. pancreas d. larynx

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.