The wheel on a road bike has a mass of 1.00 kg and a diameter of 60.0 cm (assume all the mass is in the rim). A mechanic is checking the alignment of the wheel and gives it a quick spin; it completes 5 rotations in 2.50 s. To bring the wheel to rest, the mechanic gently applies the disk brakes, which squeeze pads against the metal disk connected to the wheel. The pads touch the disk 6.00 cm from the axle, and the wheel slows down and stops in 1.50 s. Required:
a. What is the angular velocity of the wheel before they apply the brakes?
b. When the mechanic applies the brakes to stop the wheel, what is the value of the torque caused by the brakes?
c. What is the magnitude of the force that the brakes supplied? (Assume they apply a force perpendicular to the radius of the disc)

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:

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

3. dark matter

empty space could also be a simple vacuum