Answer:
2649600 Joules
Explanation:
Efficiency = 40%
m = Mass of air = 92000 kg
v = Velocity of wind = 12 m/s
Kinetic energy is given by
The kinetic energy of the wind is 6624000 Joules
The wind turbine extracts 40% of the kinetic energy of the wind
The energy extracted by the turbine every second is 2649600 Joules
Answer:
The given statement is false.
Explanation:
The spherical mirrors are the mirror that are a part of a sphere. Concave and convex mirrors are two types of spherical mirrors.
A concave mirror always forms real and inverted image. A convex mirror forms real and virtual images.
For concave mirror, the value of magnification is less that 1. Also, the focal length is negative for concave mirrors.
So, the given statement is false as a concave mirror always forms a real and inverted image. Hence, this is the required solution.
Answer:
891 excess electrons must be present on each sphere
Explanation:
One Charge = q1 = q
Force = F = 4.57*10^-21 N
Other charge = q2 =q
Distance = r = 20 cm = 0.2 m
permittivity of free space = eo =8.854×10−12 C^2/ (N.m^2)
Using Coulomb's law,
F=[1/4pieo]q1q2/r^2
F = [1/4pieo]q^2 / r^2
q^2 =F [4pieo]r^2
q = r*sq rt F[4pieo]
q=0.2* sq rt[ 4.57 x 10^-21]*[4*3.1416*8.854*10^-12]
q = 1.42614*10^ -16 C
number of electrons = n = q/e=1.42614*10^ -16 /1.6*10^-19
n =891
891 excess electrons must be present on each sphere
