In which part of the wave are the particles of the medium closer together?
a. rarefactions
b. compressions
c. solids
d. liquids

B.compressions

Explanation:

This is a characteristics of the "longitudinal waves".

Longitudinal waves are waves where the oscillation of the particles of the medium occurs in a direction parallel to the direction of propagation of the wave (an example of longitudinal waves are sound waves). As a consequence, this oscillation creates some regions where particles are closer together, and other regions where particles are more spread apart. The former are called "compressions", while the latter are called "rarefactions".

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

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