80628.0175write the numberto signifacant figures

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.

In a system, when potential energy decreases, then entropy also decreases. true false

What is the speed of an object at a given moment?