alevel解题方法（CAIE考试局ALEVEL物理PAPER2公式总结）

alevel解题方法（CAIE考试局ALEVEL物理PAPER2公式总结）resultant force F=mas=(u v)t/2v=u ats=ut 1/2 at2v2=u2 2as

距离ALevel物理（9702）的paper 2考试还剩两天！大家准备的怎么样？今天特意为大家分享As部分务必掌握的公式，相信背过并熟练掌握这些公式，对我们的考试一定有很大帮助。

Force and motion力和运动

velocity v=Δs/Δt

acceleration a=Δv/Δt

v=u at

s=ut 1/2 at2

v2=u2 2as

s=(u v)t/2

resultant force F=ma

weight W=mg

torque of a couple=force×perpendicular distance between forces

work done W=Fscosθ (θ is the angle between F and s)

gravitational potential energy GPE=mgh

kinetic energy KE=1/2 mv2

internal energy U=∑PE ∑KE

power P=W/t=Fv

momentum p=mv

resultant force F=∆p/∆t

conservation of momentum

m1 u1 m2 u2=m1 v1 m2 v2

density ρ=m/V

pressure p=F/A

pressure p=ρgh

Materials 材料学

tension F=kx

stress σ=(force))/(cross-sectional area)

strain ε=(extention))/(original length))

Young modulus E=σ/ε

elastic potential energy or strain energy

E=1/2 Fx=1/2 kx2

Electricity 电学

electric field strength E=F/Q

electric field strength in a uniform field E=-V/d

current
I=∆Q/∆t
I=nAvq

the elementary charge e=-1.6×10-19 C

potential difference V=∆W/∆Q

resistance R=V/I

power P=VI=V2/R=I2 R

work done ∆W=VI∆t

combined resistance of resistors in series

combined resistance of resistors in parallel

resistivity ρ=RA/l

terminal p.d. V=e.m.f.-Ir

potential divider circuit

electron volt 1eV=1.6×10-19J

Waves 波

frequency f=1/T

wave speed v=fλ

intensity I∝A2

constructive interference path difference=nλ=(2n)λ/2

destructive interference path difference=(2n 1) λ/2

double-slit diffraction λ=ax/D

diffraction grating dsinθ=nλ

When the observer is at rest observed frequency