55
• Diffusion: Transport of particles in random motion in the lung airway by chance
due to difference in particle concentration.
The strategy of social distancing and lockdown during Coronavirus Disease-2019
(COVID-19) pandemic in 2019 and 2020 is based on established phenomena of
physics with respect to movement of particle in the air into lungs to avoid the virus
entering the lungs. Since strict social distancing is practically not fully achievable,
as a mode of defense the people were advised to wear personal protective equipment
such as mask and face shield.
Potential and Kinetic Energies
Energy changes occur due to change in position of the object. Energy possessed by
an object due to the virtue of its position is called potential energy.
Potential energy is an energy that is “hidden” in some way that can be converted
to other forms.
Types of potential energy include the following:
• Gravitational potential energy
• Chemical energy
• Nuclear energy
• Elastic potential energy
• Electrical potential energy, especially in a capacitor
Equation for potential energy can be derived by definition of work done:
Potential energy work done force displacement
=
=
×
Free acceleration of free-falling body = g = 9.81 m/s
2
.
Mathematically,
Potential energy = mgh
Where
m = mass of the object at rest
g = acceleration due to gravity
h = height at which object is placed from reference level
Energy possessed by an object by virtue of being in motion is called kinetic
energy. An object will have kinetic energy due to its movement. If it is at rest, it will
not have any kinetic energy.
When a body falls, the potential energy stored at the top becomes converted into
kinetic energy.
The quantity of kinetic energy of an object depends on mass and velocity.
Mathematically,
Kinetic energy =
1
2
2
mv
2.2 General Physics
• Diffusion: Transport of particles in random motion in the lung airway by chance
due to difference in particle concentration.
The strategy of social distancing and lockdown during Coronavirus Disease-2019
(COVID-19) pandemic in 2019 and 2020 is based on established phenomena of
physics with respect to movement of particle in the air into lungs to avoid the virus
entering the lungs. Since strict social distancing is practically not fully achievable,
as a mode of defense the people were advised to wear personal protective equipment
such as mask and face shield.
Potential and Kinetic Energies
Energy changes occur due to change in position of the object. Energy possessed by
an object due to the virtue of its position is called potential energy.
Potential energy is an energy that is “hidden” in some way that can be converted
to other forms.
Types of potential energy include the following:
• Gravitational potential energy
• Chemical energy
• Nuclear energy
• Elastic potential energy
• Electrical potential energy, especially in a capacitor
Equation for potential energy can be derived by definition of work done:
Potential energy work done force displacement
=
=
×
Free acceleration of free-falling body = g = 9.81 m/s
2
.
Mathematically,
Potential energy = mgh
Where
m = mass of the object at rest
g = acceleration due to gravity
h = height at which object is placed from reference level
Energy possessed by an object by virtue of being in motion is called kinetic
energy. An object will have kinetic energy due to its movement. If it is at rest, it will
not have any kinetic energy.
When a body falls, the potential energy stored at the top becomes converted into
kinetic energy.
The quantity of kinetic energy of an object depends on mass and velocity.
Mathematically,
Kinetic energy =
1
2
2
mv
2.2 General Physics