)which of the following statements is accurate
a. if an object's velocity decreases, then the object is accelerating
b. if an object's velocity remains constant, it's velocity must be increasing
c if an object is said to be decelerating, it's velocity must be increasing
d. if an object's velocity is changing, it's either experiencing acceleration or deceleration

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave