Answer:
Modern communication has made our socio-economic life so much better and easier. It is easier now to communicate with someone far away on another continent and even do business and shop online without been physically present at the other end. One of the most important modern means of communication is the internet which has turned the world to a small global village.
(a) 423 J
The power of the battery is the ratio between the total energy stored (E) and the time elapsed (t):

However, the power is also the product of the voltage (V) and the current (I):

Linking the two equations together,

Since we know:
V = 9.0 V

We can calculate the total energy:

(b)
dollars
The battery has a total energy of E = 423 J. (2)
1 Watt (W) is equal to 1 Joule (J) per second (s):

so 1 kW corresponds to 1000 J/s:

Multiplying both side by 1 hour (1 h):

and
, so

So we find the conversion between kWh and Joules. So now we can convert the energy from Joules (2) into kWh:

And since the cost is $0.0660 per kilowatt-hour, the total cost will be
dollars
Answer:
30.22°.
Explanation:
Given that
height of the bridge ,h= 12 ft
The distance of the lake from bridge ,L= 7 m
Lets take angle = θ
Now by using diagram
We can say that




That is why the angle will be 30.22°.
S^2=3^2+4^2
S^2=9+16
S^2=25
S=√25
S=5m