Which statement best describes longitudinal waves?
a) particles of the wave medium move perpendicular to the direction of propagation of the wave.
b)longitudinal waves do not require a material medium for propagation.
c)particles of the wave medium move parallel to the direction of propagation of the wave.
d) particles of the wave medium move long distances from the source of the wave to carry energy.

The correct option is (C).

Explanation:

When the particles of the medium travel parallel to the direction of the propagation of the wave then the wave is said to be longitudinal wave.

It needs medium to travel. It can travel in solid, liquid and gas.

The example of the longitudinal wave is a sound wave. Sound wave consists of compression and rarefaction.

When the particles of the medium travel perpendicular to the direction of the propagation of the wave then the wave is said to be transverse wave.

Therefore, the best statement which describes the longitudinal wave is option (C).

if the forces acting on an object are unbalanced, the object will accelerate in the direction of the net force on the object.

explanation:

this is best explained by having an understanding of newton's second law, which states that f=ma. you see, when the forces are unbalanced, net force (sum of all forces) is not zero. therefore making it necessary for the object to have an acceleration in the direction of the net force.