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# PHYSICS FORMULAS

### 1. FORCE

• F = ma
• F = kx
• F = m(vf² – vi²/2S)
• F = mv/t
• F = md/t²
• F = m(vf – vi) /t
• F = Area × density × velocity²
• F = 1/2 mv²/d
• F = 1/2 Pv/d
• F = Power/velocity
• Fc = mv²/r
• Fc = mrw²
• Fc/2 = mv²/2r
• Fc = 2K.E/r
• F = Area × Stress
• F = pir² × stress
• F = YA × Strain
• F = YAl/L
• F = pressure × area
• F = change in momentum × time interval
• F = – 2mVx × Vx/2l
• F2 = F1/A1 × A2
• F = qE
• F = kQ/r²
• F = ILB sintheta
• F = q (v × B)
• F = qE + q(v × B)

### 2. Formulas related to energy and work

• Fd = k.e
• mgh = 1/2 mv²
• E = 1/2 kx²
• E = Ve
• E = nhf
• E = nhc/lambda
• E = Pc
• K.e = hf – work function = hf – hf° = hf – hc/w° (here w° is cutt off wavelength)
• E = 1/2 Pv
• mv²/2r= Fc/2
• K.E/r = Fc/2
• K.E = Fc×r/2
• K.e = 1.5 KT
• E = VQ
• E = Power × time
• E = Fvt
• % loss in K.e = v1² – v2²/v1² × 100
• % loss in P.e = h1² – h²/h1² × 100
• Energy lost due to air friction(Fh) = 1/2mv² – mgh (when body is thrown upward)
• Energy lost due to air friction(FS) = mgh – 1/2mv² (when body is thrown downward)
• E = 1/2 CV² (capacitor)
• E = R × hc (R is Rydberg’ constant)
• J = m-¹ × Js ms-¹
• hf kalpha x rays = EL – Ek
• hf kbeta x rays = EM – Ek
• Binding energy = mass defect × c²
• W = Fd Costheta
• W = nmgh (when person is climbing stairs)
• W = n(m+m) gh (when person is climbing stairs with some load)
• W = 0mgh + 1mgh + 2mgh + 3mgh ……. (in case of stacking bricks. For ist brick h=0. For 2nd brick h=1. For 3rd brick h=2 and so on)
• W = Fd = PA × change in V
• W = Q – change in U
• Q = mc × change in T
• T/273.16 = Q/Q3 (Thermodynamic scale)
• W = I²Rt
• W = emf×charge
• W = VQ
• W = 1/2 lF
• W = YAl²/2L
• W = StressAl²/2Strain
• W = PressureAl²/2Strain
• W = Fl²/2Strain

• P = Fv
• P = E/t
• P = n(mgh/t)
• P = Fd/t
• P = mv²/2t

### 4. Formulas related to distance, displacement, velocity and acceleration

• d = vt
• d = at²
• d = (vf + vi/2) ×t
• d = 5t² (for distance in ‘n’ seconds)
• d = 5(2tn – 1) (for distance in ‘nth’ second)
• d = 1/2 mv²/F
• d = vit + 5t²
• d = v × underroot 2H/g
• d = vt = x°wt = x°2pi/T × t = x°2pift
• x = x° Sin wt
• x = x° Sin (underroot k/m) t
• vf = vi + at
• 2as = vf² – vi²
• 2as = (vi + at)² – vi²
• 2as = vf² – (vf – at) ²
• v = underroot Vfx² + Vfy²
• v = Power/Force
• v = 2×K.E/momentum (k.e = 1/2 Pv)
• v² = 2×Power×time/mass (P = mv²/2t)
• v = underroot 2as
• v = underroot gr (speed at highest point in a verticle circle)
• v = underroot 5gr (speed at lowest point in a verticle circle)
• v² = 2FS/m
• v² = 2E/m
• v² = 2Ve/m
• v = eBr/m (velocity of particle under action of magnetic force along circular path)
• v² = Force/Area.Density
• v = w underroot x°² – x²
• v = underroot k/m × underroot x°² – x²
• v = x°w (at mean position where x=0)
• v = x° underoot k/m
• v = v° underroot 1 – x²/x°² (for determining ratio b/w inst. Velocity and maxi. Velocity)
• v= x°2pif = x°2pi/T
• a = x°w² = x°w.w = vw = v.2pif
• Common velocity = m1v1/m1+m2
• vi² = Rg/Sin2theta
• v = underoot Tension×length/mass
• V = 2pi ke²/nh (speed of e- in nth orbit)
• Vn = V/n
• v = nh/2pimr (lambda = 2pir and lambda=h/p)
• ma = kx
• a = kx/m (SHM)
• a = – gx/l (Simple pendulum)
• ac = v²/r

### 5. Formulas related to wavelength ‘w’

• w = v/f
• w = 1/wave number
• w1 = 2l (when pipe is opened at both ends)
• w1 = 4l (when pipe is opened at one end)
• Delta w = Us/f (doppler shift)
• Wavelength for obs. = w – delta w = v/f – Us/f
• w = hc/Ve
• w = hc/E
• w = h/mv
• w = h/P as P = underroot 2mE so
• w = h/underroot 2mE (de Broglie wavelength)
• w = underroot 150/V A° (short method for de Broglie wavelength. This formula is applicable only for e-)
• 1/w = RH (1/p²-1/n²)
• Wmaxi/Wmini = n²/n²-p² (for determining ratio b/w maxi. Wavelength to mini. Wavelength for series of atomic spectrum)
• w = 2pir/n (n is no. of loops in a circle)
• h/mv = 2pir

Hope you found useful,