Sound travels about 750 miles per hour. if you stand in a canyon and sound a horn, you will hear an echo. suppose it takes about 4 seconds to hear the echo. how far away is the canyon wall, in feet? (hint: the distance to the canyon wall is half the distance the sound travels)

The answer to your question is:         d = 0.417 mi

Explanation:

Data

Speed of sound = 750 mi/h

time = 4 seconds

distance = ?

Formula

               s = d / t

time = 2 seconds because in 2 seconds the sounds goes goes from me to the canyon and in two seconds it comes back.

Convert 2s to hours

                             3600 s 1 h

                                    2 s    x

                                   x = (2 x 1)/3600

                                   x = 0.00056 h

Substitution

                         d = v x t

                         d = 750 mi/h x 0.00056 h

                        d = 0.417 mi

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: