Answer:
1) not so long (maybe an hour or two)
2) access to information through the internet will be most affected if my computer and mobile phone run out of battery power.
3) yes, one should prepare for power outage. This can be done by having a standby alternative source of power like the use of inverters that stores electrical energy in form of chemical energy, and small internal combustion engine powered electric generators.
4) solar panels can be used to draw power from incident sun rays, this power can be stored in an inverter for future use in case of a power outage.
5) energy from the sun is converted into direct current which is then supplied to an accumulator in the opposite direction to its flow of current. When the energy is needed, it can be used directly, or converted to an alternating current. This is achieved by connecting its terminal to the supply. Electric field is generated by flow of ions and electrons within the working chemical (e.g lithium).
Explanation:
T is in seconds (s)
<span>2pi is dimensionless </span>
<span>L is in meters (m) </span>
<span>g is in meters per second squared (m/s^2) </span>
<span>so you can write the equation for the period of the simple pendulum in its units... </span>
<span>s=sqrt(m/(m/s^2)) </span>
<span>simplify</span>
<span>s=sqrt(m*s^2*1/m) cancelling the m's </span>
<span>s=sqrt(s^2) </span>
<span>s=s </span>
<span>therefore the dimensions on the left side of the equation are equal to the dimensions on the right side of the equation.</span>
Answer:
b) 900 W
Explanation:
The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:
P = V*i
1500 = 120*i
i = 12.5 A
So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:
P = 120*7.5
P = 900 W
Answer: 
Explanation:
According to Newton's 2nd Law of motion the force 
is proportional to the mass 
and acceleration 
:
(1)
On the other hand, the equation for the Centripetal force is:
(2)
Where:
is the velocity
is the radius of the circular motion
Making (1) and (2) equal:
(3)
Hence:
This is the expression for the centripetal acceleration
It should be noted, this acceleration is directed toward the center of the circumference of the circular motion (that's why it's called centripetal acceleration).
Unlike acceleration and velocity, speed does not need to specify the direction of motion. Speed is a scalar quality.
