Answer:
4.7m
Explanation:
Given parameters:
Mass of the book = 1kg
Gravitational potential energy = 46J
Unknown:
Height of the shelf = ?
Solution:
The potential energy is due to the position of a body above the ground.
Gravitational potential energy = mgh
m is the mass,
g is the acceleration due gravity = 9.8m/s²
h is the height which is unknown
46 = 1 x 9.8 x h
h = 4.7m
A region within a magnetic material in which magnetization is in a uniform direction this means the individual magnetic moments of the atoms are aligned with one another and they point the same direction. when cooled bwlow a temperature called the curie temperature the magnetization of a piece of ferromagnetic material.<span />
Answer:
The fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is

Explanation:
From the question we are told that
The time constant 
The potential across the capacitor can be mathematically represented as

Where
is the voltage of the capacitor when it is fully charged
So at


Generally energy stored in a capacitor is mathematically represented as

In this equation the energy stored is directly proportional to the the square of the potential across the capacitor
Now since capacitance is constant at
The energy stored can be evaluated at as


Hence the fraction of the energy stored in an initially uncharged capacitor is

Potential energy = mass x gravity x height
P.E = 4 x 9.8 x 3
P.E = 117.6 J