Complete Question
In lightning storms, the potential difference between the Earth and the bottom of the thunderclouds can be as high as 350 MV (35,000,000 V). The bottoms of the thunderclouds are typically 1500 m above the earth, and can have an area of 120 km^2. Modeling the earth/cloud system as a huge capacitor, calculate
a. the capacitance of the earth-cloud system
b. the charge stored in the "capacitor"
c. the energy stored in the capacitor
Answer:
a
b
c
Explanation:
From the question we are told that
The potential difference is 
The distance of the bottom of the thunderstorm from the earth is d = 1500 m
The area is 
Generally the capacitance of the earth cloud system is mathematically represented as
Here 
is the permitivity of free space with as value 
So
=>
Generally the charge stored in the capacitor (earth-cloud system) is mathematically represented as
=> 
=>
Generally the energy stored in the capacitor is mathematically represented as
=> 
=>
Answer: 292.95 J
Explanation:
change in internal energy= Heat transfer - work done
ΔU =Q -PΔV
Here, Q = 0 as there is no heat transfer.
P =2.00 atm = 2.00 × 101235 Pa = 202470 Pa
ΔV = final volume - initial volume = 0.8 V -V = -0.2 V
where V is the initial volume.
Volume of a spherical ball, 
r = d/2 = 23.9 cm / 2 = 0.12 m
Hence, internal energy would change by 292.95 J.
Answer:
the focal length of the mirror is : 
Explanation:
Use the formula for the formation of image using a divergent mirror and recalling that the image (s') that this mirror formed is virtual, so it is entered as a negative number in the formula. Use the object position (s) as 10, the image position (s') as -2, and derive the value of the focal length:
Answer:
option B
Explanation:
The correct answer is option B
When the displacement in the harmonic motion is maximum then kinetic energy at the maximum point is minimum and the potential energy is maximum at that point.
So, when the displacement is maximum, spring force magnitude is also maximum because the force is proportional to the displacement and also the magnitude of the acceleration is maximum so, the net force is also maximum.
Explanation:
The principle of an electric motor is based on the current carrying conductor which produces magnetic field around it. A current carrying conductor is placed perpendicular to the magnetic field so that it experiences a force.
The largest electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives.
