College physics formula - Education and Training Encyclopedia

College physics formula

University physics formula set

Basic concepts (definitions and related formulas)

Position vector:, in rectangular coordinate system:; Angular position: θ

Speed: average speed: speed: () angular speed:

Relationship between angular velocity and speed: V=rω.

Acceleration: or average acceleration: angular acceleration:

In the natural coordinate system, where (=rβ), (=r2 ω).

1. Force: =m (or =) Moment: (size: M=rFcosθ direction: right-handed spiral rule)

2. Momentum:, angular momentum: (size: L=rmvcosθ direction: right-hand spiral rule)

3. Impulse: (= δ t); Work: (gas does external work: A=∫PdV)

Mg (gravity) → mg hour

-kx (elasticity) → kx2/2

F= (gravity) → =Ep

(electrostatic force) →

4. Kinetic energy: mV2/2

5. Potential energy: abao =-Δ EP Different interaction forces, different forms of potential energy, and different zero points. In the case of default potential energy zero:

Mechanical energy: E=EK+EP

6. Heat: Among them, molar heat capacity C is related to the process, and the relationship between constant volume heat capacity Cv and constant pressure heat capacity Cp is: CP = Cv+R.

7. Pressure:

8. Molecular average translational energy: internal energy of ideal gas;

9. Maxwell velocity distribution function: (meaning: the proportion of molecules in the unit velocity interval near V)

10. Average rate:

Root mean square rate:; Most likely ratio:

1 1. Entropy: s = klnω (ω is thermodynamic probability, that is, the number of microscopic states contained in a macroscopic state).

12. Electric field strength: = /q0 (point charge:)

13. Potential: (point charge); Electric potential energy: wa = qua (a =-Δ w)

14. capacitance: c = q/u; Capacitive energy storage: w = Cu2/2; Electric field energy density ωe=ε0E2/2

15. magnetic induction intensity: order of magnitude, b = fmax/qv (t); Direction, the small magnetic needle points (S→N).

Laws and theorems

1. Vector superposition principle: any vector can be regarded as the sum of its independent components. Namely: = σ (replace the formula with,,, and become the superposition principle of position, speed, acceleration, force, electric field intensity and magnetic induction intensity respectively).

2. Newton's law: =m (or =); Newton's third law:' =; Law of universal gravitation:

3. Momentum Theorem :→ Conservation of Momentum: Conditions

4. Theorem of angular momentum :→ Conservation of angular momentum: conditions

5. Principle of kinetic energy: (Definition of relative potential energy:)

6. Functional principle: an exterior+an unguaranteed interior = Δ e→ conservation of mechanical energy: Δ e = 0 Condition: an exterior+an unguaranteed interior = 0.

7. Equation of state of ideal gas: or P=nkT(n=N/V, k=R/N0)

8. Principle of energy sharing: In an equilibrium state, each degree of freedom of a substance molecule has the same average kinetic energy, which is kT/2.

Clausius pointed out that it is impossible to transfer heat from a low-temperature object to a high-temperature object without other effects.

Kelvin said: It is impossible to absorb heat from a single heat source and turn it into useful work without other influences.

Essence: The process in an isolated system always changes from a macroscopic state with low thermodynamic probability to a state with high thermodynamic probability. In other words, the process that occurs in an isolated system always goes along the direction of increasing disorder.

9. The first law of thermodynamics: Δ e = q+a.

10. The second law of thermodynamics: isolated system: δ s >; 0

(Entropy increasing principle)

1 1. Coulomb's law:

(k = 1/4ω0)

12. Gauss theorem: (electrostatic field is active field) → infinite plate: E=σ/2ε0.

13. Loop theorem: (electrostatic field is conservative because it does not rotate)

θ2

r P o R

θ 1

14. Biot-Savart Law:

Direct current-carrying conductor: