A 200-kg communications satellite is placed into a circular orbit around Earth with a radius of $4.23 \times 10^7 \mathrm{~m}$ (26,300 miles) (a) Find the gravitational force on the satellite. (There is some useful information in Section 2.7.) (b) Use the equation for centripetal force to compute the speed of the satellite. (c) Show that the period of the satellite-the time it takes to complete one orbit-is 1 day. (The distance it travels during one orbit is $2 \pi$, or $6.28$, times the radius.) This is a geasynchronous orbit: the satellite stays above a fixed point on Earth's equator.

Walmart contended with a widespread text-messaging hoax that warned women to stay away from its stores or risk death. The digital rumor apparently originated in an urban myth (an unsubstantiated "fact" that many people accept as true) that circulated via email several years ago. As a reflection of how widespread this myth became, at one point Walmart was number 5 on Twitter's list of trending topics. If you were a Walmart communications executive, how might you deal with this kind of public relations nightmare?

A telephone company is planning to introduce two types of communications systems that it hopes to sell to its largest commercial customers. To create a model to determine the maximum profit, it is assumed that if the first product is priced at x hundred dollars each and the second type at y hundred dollars each, approximately 40 - 8x + 5y consumers will buy the first product and 50 + 9x - 7y will buy the second type. If the cost of manufacturing the first type is $1,000 each and the cost of manufacturing the second type is$3,000 each, how should the telephone company price the systems to generate maximum profit?

Draw the directed graph that represents the data in the communications matrix.

$$\begin{array}{r} P \\ Q \\ R \\text{\S} \\ T \end{array} \normalsize \overset{P\quad Q\quad R \quad S \quad T} {\left[\begin{array}{} 1 & 1 & 0 & 0 & 1 \\ 1 & 0 & 0 & 1 & 0 \\ 0 & 1 & 1 & 0 & 1 \\ 1 & 1 & 1 & 0 & 0 \\ 0 & 0 & 1 & 1 & 1 \end{array}\right]}\begin{array}{ll}\end{array}$$

A spherical communications satellite, $2 \mathrm{~m}$ in diameter, is placed in orbit around the earth. The satellite generates $1000 \mathrm{~W}$ of internal power from a small nuclear generator. If the surface of the satellite has an emittance of $0.3$, and is shaded from solar radiation by the earth, estimate its surface temperature. What would the temperature be if the satellite with an absorptivity of $0.2$ were in an orbit in which it would be exposed to solar radiation? Assume the sum is a blackbody at $6,700 \mathrm{~K}$ and state your assumptions.

Goldstar Communications was organized on December 1 of the current year and had the following account balances at December 31, listed in tabular form:

$$\begin{array}{|cc} & & \text{Assets} & & = & \text{Liabilities} & + & \text{Owner's Equity} \\ \hline &\text{Cash} + & \text{Land} + & \text{Building} + & \text{Office equipment}= & \text{ Notes Payable} + & \text{Accounts Payable} + &\text{Capital stock} \\ \hline \\ \text{Balances} & \$37,000 & \$95,000 &\$125,000 &\$51,250&\$80,000& \$28,250 & \$200,000 \\ \end{array}$$

Early in January, the following transactions were carried out by Goldstar Communications:

1. Sold capital stock to owners for $\$ 35,000$.
2. Purchased land and a small office building for a total price of $\$ 90,000$, of which $\$ 35,000$ was the value of the land and $\$ 55,000$ was the value of the building. Paid $\$ 22,500$ in cash and signed a note payable for the remaining $\$ 67,500$.
3. Bought several computer systems on credit for $\$ 9,500$ (30-day open account).
4. Obtained a loan from Capital Bank in the amount of $\$ 20,000$. Signed a note payable.
5. Paid the $\$ 28,250$ account payable due as of December 31 .
   Instructions
   a. List the December 31 balances of assets, liabilities, and owners' equity in tabular form as shown.

India's Tata Steel has reorganised its management structure to realise its corporate goal of becoming a leading player in the global steel industry. The company has formed a centralised body to create common strategies across the whole group, which has steelworks in the UK, Thailand and the Netherlands as well as India. The functions that will be centralised will be technology, finance, corporate strategy and corporate communications.

Outline the difference between centralised and decentralised decision-making structures in an organisation like Tata.

While describing a circular orbit 200 mi above the earth, a space vehicle launches a 6000-lb communications satellite. Determine (a) the additional energy required to place the satellite in a geosynchronous orbit at an altitude of 22,000 mi above the surface of the earth, (b) the energy required to place the satellite in the same orbit by launching it from the surface of the earth, excluding the energy needed to overcome air resistance. (A geosynchronous orbit is a circular orbit in which the satellite appears stationary with respect to the ground.)

Telstar Communications is going to purchase an asset for $\$380,000$ that will produce $180,000 per year for the next four years in earnings before depreciation and taxes. The asset will be depreciated using the three-year MACRS depreciation schedule in Table 12-12. (This represents four years of depreciation based on the half-year convention.) The firm is in a 35 percent tax bracket. Fill in the following schedule for the next four years:

Earnings before depreciation and taxes _________

Depreciation _________

Earnings before taxes _________

Taxes _________

Earnings after taxes + Depreciation _________

Cash flow _________

Consider the following program:

boolean blocked [2]; 
int turn; 
void P (int id) 
{
while (true) { 
blocked[id] = true; 
while (turn != id) { 
while (blocked[1-id]) 
/* do nothing */; 
turn = id; 
}
/* critical section */ 
blocked[id] = false; 
/* remainder */ 
 } 
}
void main() 
{
blocked[0] = false; 
blocked[1] = false; 
turn = 0; 
parbegin (P(0), P(1)); 
}

This software solution to the mutual exclusion problem for two processes is proposed in [HYMA66]. Find a counterexample that demonstrates that this solution is incorrect. It is interesting to note that even the Communications of the ACM was fooled on this one.

A communications satellite moves in a circular orbit around Earth at a distance of 42,000 kilometers from the center of Earth. The angular velocity dθ/dt = ω = π/12 radian per hour is constant. (a) Use polar coordinates to show that the acceleration vector is given by a = d²r/dt² = [d²r/dt² - r(dθ/dt)²] u_r + [r d²θ/dt² + 2 dr/dt dθ/dt]u_θ where u_r = cos θi + sin θj is the unit vector in the radial direction u_θ = -sin θi + cos θj

The Federal Communications Commission is attempting to locate an illegal radio station. It sets up two monitoring stations, $\mathrm{A}$ and $\mathrm{B}$, with station $\mathrm{B} \ 40$ miles east of station $\mathrm{A}$. Station $\mathrm{A}$ measures the illegal signal from the radio station as coming from a direction of $48^{\circ}$ east of north. Station $\mathrm{B}$ measures the signal as coming from a point $34^{\circ}$ west of north. How far is the illegal radio station from monitoring stations $\mathrm{A}$ and $\mathrm{B}$ ? Round to the nearest tenth of a mile.

Metzler Communications designs and programs a website for a local business. Metzler charges $46,000 for the project, and the local business signs an 8% note January 1, 2019.

Required:

1. Prepare the journal entry to record the sale on January 1, 2019.

2. Determine how much interest Metzler will receive if the note is repaid on October 1, 2019.

3. Prepare Metzler’s journal entry to record the cash received to pay off the note and interest on October 1, 2019.

Ericsson, a Swedish networks and communications firm, reported a gross value of inventory of SEK25,227 on December 31. It also reported an ending balance in the allowance for impairments of SEK2,752 million. During the year, Ericsson recognized a write-down of inventory in the amount of SEK1,276 million. Assume the acquisition cost of the inventory written down is SEK3,500 million. Ericsson applies IFRS and reports its results in millions of Swedish kronor (SEK). c. Suppose that in January of the next year, the market value of the impaired inventory increased to SEK2,800. What journal entry, if any, would Ericsson make?