Find the formulas and letter explanations for all the problems in physics 5

m, m, s, second.

min, minutes.

h, hour. m s, meters per second.

f, which indicates the frequency.

Hz, hertz, unit of frequency; Celsius.

t, which indicates time or temperature.

f, the focal length of the lens, in m

f, the focal point of the lens, the density, in kg m3 or g cm3

m, mass, in kg, t (tons) or g

n, the unit of force in Newton, can also denote a supporting force or pressure.

f, which denotes force.

p, power. p, pressure.

g, gravity. g, which means efficiency.

w, the unit of work or power in watts.

q, heat. j, joules, a unit of energy and heat.

kw, kilowatts.

Force 1, pressure: p=f s

p represents pressure, the unit pascal (abbreviated pa, symbol pa) f represents pressure, and the unit is newton (n).

s indicates the stressed area, in square meters.

2. Liquid pressure and buoyancy: f= gh

3. Density = m v

Density, m quality

v denotes volume.

4. Gravity g=mg

5. Speed. v=s/t

6. Work w=fs

w denotes work, f denotes work).

7. Power p=w t fv

8. Mechanical efficiency w useful w total gh fs=g fn (n is the number of strands of the pulley group).

9. Thermal energy q cm t

10. Calorific value q=mq

11. Sliding friction f= n

f is the sliding friction.

n is positive pressure.

is a friction factor and unitless).

Electricity 1, Ohm's law: i = u r

2. Electric work: w uit pt i rt u rt (the last 2 formulas are applicable to pure resistive circuits).

3. Electric power: p=ui w t i r u r common data:

The speed of light in a vacuum.

3 10 8 m sec.

Newton kilograms.

15°C in air.

340 m sec.

Safety voltage. Not higher than 36 volts for reference.

A unit of physical quantity.

The name of the formula. The name of the symbol.

Symbol mass m kg.

kgm = pv temperature t

°C velocity v

m s

v = s t density p

kilogram m kg m

p = m v force (gravity).

F Newton (Ox).

ng = mg pressure p

Pascal (Pa).

pap = f s work w

Joules (joules) jw = fs power p

Watt (Watt) WP = W t Current I

Amps (amps) ai = u r voltage u

Volts (volts) vu = IR resistance r

Ohm (ohm) r = u i electrical work w

Joules (coul) jw=uit

Electrical power watts (watts).

WP=W t=ui heat q

Joule (coul) jq = cm (t-t°) specific heat c

Joules (kg°C).

j/(kg°c)

The speed of light in a vacuum.

3 10 8 m sec.

Newton kilograms.

15°C in air.

340 m sec.

Safety voltage. Not higher than 36 volts.

Gravitational potential energy. mgh

Elastic potential energy = kx is half of the kinetic energy of the elastic material stiffness coefficient and the square product of the stretch (contraction length) =

That is, half of the square product of mass and velocity.