What are the factors that affect density of a liquid

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 is the best for showing percentages of different types of cars sold(gas hybrid , electric , other ) in the united states ?

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain