# Physics formulas

In physics, the formulas represent the relationships between quantities involved in the same physical phenomenon. However, it is essential to know the meaning of each quantity and understand the context in which each formula is applied.

The units below are expressed in the international unit system and appear in parentheses in the parameter description.

Kinematics

The kinematics addresses aspects related to the movement of the bodies.

The kinematics makes a description of the movement of the bodies, without worrying about the causes. Speed, distance traveled, time and acceleration are some of the parameters studied in this area.

Uniform line movement

s: end position (m)
0 : start position (m)
v: speed (m / s)
t: time interval

Uniformly varied rectilinear motion

s: final position (m)
0 : initial position (m)
0 : initial velocity (m / s)
a: acceleration (m / s 2 )
t: time interval

v: final velocity (m / s)
0 : initial velocity (m / s)
a: acceleration (m / s 2 )
t: time interval (s)

v: final speed (m / s)
0 : initial speed (m / s)
a: acceleration (m / s 2 )
ΔS: distance traveled

Uniform circular motion

v: velocity (m / s)
ω: angular velocity (rad / s)
R: radius of curvature of the path (m)

T: period (s)
f: frequency (Hz)

ω: angular velocity (rad / s)
f: frequency (Hz)

cp : centripetal acceleration (m / s 2 )
v: velocity (m / s)
R: radius of curvature of the path (m)

Oblique launch

x : speed on X axis – constant speed (m / s)
0 : initial speed (m / s)
θθ: angle of launch direction

0y : initial velocity on the y axis (m / s)
0 : initial velocity (m / s)
θ: angle of launch direction

y : speed on the y-axis (m / s)
0y : initial speed on the y-axis (m / s)
a: acceleration (m / s 2 )
t: time interval (s)

H: maximum height (m)
0 : initial velocity (m / s)
θ: launch direction angle
g: gravity acceleration (m / s 2 )

A: reach (m)
0 : initial velocity (m / s)
θ: launch direction angle
g: gravity acceleration (m / s 2 )

Dynamic

Rocket launching requires studying the causes of movement.

Dynamics studies the causes of body movement. In this area, the different types of forces involved in movement are studied.

R : resultant force (N)
m: mass (kg)
a: acceleration (m / s 2 )

P: weight (N)
m: mass (kg)
g: acceleration due to gravity (m / s 2 )

fr : friction force (N)
µ: friction coefficient
N: normal force (N)

el : elastic force (N)
k: elastic spring constant (N / m)
x: spring deformation (m)

Work, energy and power

By moving a rock, we are doing a job.

Conservation of energy is one of the fundamental principles of physics and its understanding is extremely important. Work and power are two quantities that are also related to energy.

T: work (Joule, J)
F: force (Newton, N)
d: displacement (meter, m)
θ: angle between the direction of the force and the displacement

c : kinetic energy (Joule, J)
m: mass (kilogram, kg)
v: speed (meters / second, m / s)

p : gravitational potential energy (Joule, J)
m: mass (kilogram, kg)
g: acceleration due to gravity (meters / second 2 , m / s 2 )
h: height (meters, m)

el : elastic potential energy (Joule, J)
k: elastic spring constant (Newton / meter, N / m)
x: spring deformation (meters, m)

P: power (watt, w)
T: work (Joule, J)
Δt: time interval (seconds, s)

Movement quantity

Q: amount of movement (kg.m / s)
m: mass (kg)
v: speed (m / s)

Impulse

I: impulse (Ns)
F: force (N)
Δt: time interval (s)

• Types of energy
• Kinetic energy

Hydrostatic

In hydrostatics fluids at rest, whether liquid or gas, are studied. Push and pressure are fundamental concepts in this area.

p: pressure (N / m 2 )
F: force (N)
A: area (m 2 )

ρ: density (kg / m 3 )
m: mass (kg)
V: volume (m 3 )

t : total pressure (N / m 2 )
atm : atmospheric pressure (N / m 2 )
ρ: density (kg / m 3 )
g: acceleration due to gravity (m / s 2 )
h: height (m)

E: thrust (N)
ρ: density (kg / m 3 )
g: acceleration due to gravity (m / s 2 )
V: volume of displaced liquid (m 3 )

Universal gravitation

The movement of the celestial bodies is explained with the laws of gravitation.

The Kepler ‘s laws and the law of universal gravitation Isaac Newton contributed greatly to the advancement of astronomy.

T: period of the planet (ua)
K: constant of proportionality

G : gravitational force (N)
G: universal gravitational constant (Nm 2 / kg 2 )
1 : body mass 1 (kg)
2 : body mass 2 (kg)
d: distance (m)

Thermology and thermodynamics

Thermometers can use different scales to measure temperature.

In thermology the concept of temperature, heat and thermometric scales is studied, in addition to the effects of temperature variation on the dilation of bodies. In thermodynamics, the relationship between heat and work is learned.

Conversion of temperature scales

C : temperature in degrees Celsius (ºC)
F : temperature in Fahrenheit (ºF)

K : temperature in Kelvin (K)
C : temperature in Celsius (ºC)

Thermal expansion

∆L: linear expansion (m)
0 : initial length (m)
α: coefficient of linear expansion (ºC -1 )
∆T: temperature variation (ºC)

∆A: surface expansion (m 2 )
0 : initial area (m 2 )
β: coefficient of surface expansion (ºC -1 )
∆T: temperature variation (ºC)

∆V: volumetric expansion (m 3 )
0 : initial volume (m 3 )
Y: volumetric expansion coefficient (ºCm -1 )
∆T: temperature variation (ºC)

Calorimetry

C: thermal capacity (J / ºC)
m: mass (kg)
c: specific heat (J / kg ºC)

Q: amount of heat transferred (J)
m: mass (kg)
c: specific heat (J / kg.ºC)
ΔT: temperature variation (ºC)

Q: amount of heat for phase change (J)
m: mass (kg)
L: latent heat according to phase change (J / kg)

Thermodynamics

ΔU: variation of internal energy (J)
Q: quantity of heat (J)
T: work (J)

T: work (J)
q : amount of heat absorbed from the hot source (J)
f : amount of heat released by the cold source (J)

R: performance of a thermal machine
T: work (J)
q : amount of heat absorbed from the hot source (J)

∆S: variation of entropy (J / K)
∆Q: quantity of heat (J)
T: absolute temperature (K)

Waves and optics

Sound is a wave.

In the study of waves, the fundamental equation is basically used, while, in optics, reflection and refraction are the important phenomena for the study of mirrors and lenses.

Wave propagation speed

v: velocity of propagation of a wave (m / s)
λ: wavelength (m)
f: frequency (Hz)

Spherical mirrors

f: focal length (cm om)
p: vertex distance from mirror to object (cm om)
p ‘: vertex distance from mirror to image (cm om)

A: transverse linear magnification
i: image size (cm om)
o: object size (cm om)
p ‘: vertex distance from mirror to image (cm om)
p: vertex distance from mirror to object (cm om)

Refraction

1 : refractive index of the medium 1
θ 1 : angle of incidence
2 : refractive index of the medium 2
θ 2 : angle of refraction

Electricity

Concepts such as electric current, potential difference, power, and electrical energy are fundamental to calculations in electricity.

Electrostatics

e : electrostatic force (N)
k: electrostatic constant (Nm 2 / C 2 )
| Q 1 l: modulus of charge 1 (C)
| Q 2 |: modulus of charge 2 (C)

F: electrostatic force (N)
q: test charge (C)
E: electric field (N / C)

V: electric potential (V)
k: electrostatic constant (Nm 2 / C 2 )
Q: electric charge (C)
d: distance (m)

Electricity

V: potential difference (volts, V)
R: resistance (Ohm, Ω)
I: current (Ampere, A)

P: electrical power (Watts, W)
V: potential difference (volts, V)
I: current (Ampere, A)

P: Joule effect power (J)
R: electrical resistance (Ω)
I: current (A)

E: electrical energy (J or KWh)
P: power (J or kW)
Δt: time interval (soh)

Association of series resistors

e : equivalent resistance (Ohm, Ω)
1 : resistance 1 (Ω)
2 : resistance 2 (Ω)
n : resistance n (Ω)

Parallel resistance association

e : equivalent resistance (Ω)
1 : resistance 1 (Ω)
2 : resistance 2 (Ω)
n : resistance n (Ω)

Capacitors

C: capacitance (F)
Q: electric charge (C)
V: potential difference (V)

• Ohm’s law.
• Electricity.

Electromagnetism

The hard drive of computers works thanks to electromagnetic principles.

The variation of the electric current creates a magnetic field and the variation of the magnetic field induces a current. In this area, electricity and magnetism come together to form an important field of physics.

m : magnetic force (N)
B: magnetic induction vector (T)
| q |: modulus of charge (C)
v: velocity (m / s)
θ: angle between vector B and velocity

m : magnetic force (N)
B: magnetic induction vector (T)
I: current (Amp)
l: cable length (m / s)
θ: angle between vector B and current

φ: magnetic flux (Wb)
B: magnetic induction vector (T)
A: area (m 2 )
θ: angle between vector B and the vector normal to the surface of the spiral

ε: induced emf (V)
Δφ: variation of magnetic flux (Wb)
Δ t: time interval (s)