A uniform 5.50-kg square solid wooden gate 2.00 m on each side hangs vertically from a frictionless pivot at its upper edge. A 1.00-kg raven flying horizontally at 5.00 m/s flies into this door at its center and bounces back at 2.00 m/s in the opposite direction. What is the angular speed of the gate just after it is struck by the unfortunate raven?

ω = 0.9545 rad/s

Explanation:

In this question, angular momentum is conserved.

Thus;

Initial angular momentum = final angular momentum.

Thus, L_1 = L_2

So,

m•v1•l = -m•v2•l + I_gate•ω

So;

m•v1•l + m•v2•l = I_gate•ω

l = l/2

So,we now have;

(ml/2)•(v1 + v2) = I_gate•ω

Now, I_gate is expressed as Ml²/3

Where M is mass of gate = 5.5 kg.

So,

(ml/2)•(v1 + v2) = (Ml²/3)•ω

ω = [3ml(v1 + v2)]/2Ml²

This will reduce further to;

ω = [3m(v1 + v2)]/2Ml

Where m is mass of raven = 1 kg

v1 = 5 m/s

v2 = 2 m/s

l = 2m

So;

ω = [3(1)(5 + 2)]/(2×5.5×2)

ω = 3×7/22

ω = 0.9545 rad/s

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: