A rock falls from a tower that is 320 feet high. As it is falling, its height is given by the formula h equals 320 minus 16 t squared . How many seconds (in tenths) will it take for the rock to hit the ground (hequals0)?

a. 4.5secs

Explanation:

From the question, the equation describing the height is given by

at the point when the rock hit the ground, the height,h will be zero.

Hence we can have

hence the rock will hit the ground in 4.5secs

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:

multiply 2kg by latent heat of vap