From the concept of optics on a curvature of a spherical mirror, the proportion for which the focal length is equivalent to half the radius of curvature is fulfilled. Mathematically this is

Here,
f = Focal Length
R = Radius
Rearranging to find the radius we have,

Replacing with our values,
R = 2(13.8cm)
R = 27.6cm
Therefore the radius of the spherical surface from which the mirror was made is 27.6cm
Answer:
density = 5520 kg/m^3
Explanation:
given that
radius of earth = 6378 km
G = 6.67 x 10⁻¹¹ m³/kg.s²
g = 9.80 m/s²
we know,

mass of earth


M = 5.972 x 10²⁴ kg
density =
V = volume of the earth = 4/3πr³
V = 4/3 x 3.14 x (6378 x 10³)³
V = 1.08 x 10²¹ m³
density = 
density = 5.52 x 10³ kg/m^3
density = 5520 kg/m^3
Answer:
Option a. the number of transistors per square inch on integrated circuits will double every two years.
Explanation:
Moore's law states that the number of transistors in an integrated circuit will double every two years.
Answer:
Its duration is 1.85*10⁻³ s or 1.85 ms
Explanation:
The intensity of electric current I is defined as the amount of electric charge Q (measured in Coulombs) that passes through a section of a conductor in each unit of time. The letter I is used to name the Intensity and its unit is the Ampere (A).
The intensity of electric current is expressed as:

where:
I: Intensity expressed in Amps (A)
Q: Electric charge expressed in Coulombs (C)
t: Time expressed in seconds (s)
Being:
Replacing:

Solving:
19500 A*t= 36 C

t= 1.85*10⁻³ s= 1.85 ms (being 1 s= 1,000 ms)
<u><em>Its duration is 1.85*10⁻³ s or 1.85 ms</em></u>
Volumetric cylinders and volumetric flasks