To report the of an object, we must specify both its speed and its direction .

Distinguish between a transverse wave and a longitudinal wave.

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.

Properties seen when one one substance changes to another are known as properties