Sound—energy<span> we can hear—travels only so far before it soaks away into the world around us. Until electrical </span>microphones<span>were invented in the late 19th century, there was no satisfactory way to send </span>sounds<span> to other places. You could shout, but that carried your words only a little further. You couldn't shout in New York City and make yourself heard in London. And you couldn't speak in 1715 and have someone listen to what you said a hundred years later! Remarkably, such things are possible today: by converting sound energy into electricity and information we can store, microphones make it possible to send the sounds of our voices, our music, and the noises in our world to other places and other times. How do microphones work? Let's take a closer look!</span>
Answer:
a = 4.96 m/s²
Explanation:
Given,
The mass of the box, m = 51 Kg
The magnitude of the applied force, Fₐ = 485 N
The friction force on the box, Fₓ = 232 N
The net force acting on the box is,
F = Fₐ - Fₓ
Substituting the given values in the above equation
F = 485 - 232
= 253 N
The acceleration of the crate is given by
a = F/m
= 253 / 51
= 4.96 m/s²
Hence, the acceleration of the crate is, a = 4.96 m/s²
Nuclear fusion and heat (thermal) energy
Answer:
True.
Explanation:
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
