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Topic A

Ideas

o        If m1=m2 and moving 1 collides with stationary 2, then v1=0, v2=u1 i.e. the second ball moves off with the original velocity of the first and the first remains stationary

o        If m1<<m2 and minute mass 1 collides with massive stationary mass 2 then v1-u1 and v20

o        If m1>>m2 and massive mass 1 collides with stationary minute mass 2 then v1-u1 u1 and v22u1

Equations

 

Recall and use:

         E= mv2 Kinetic Energy = x mass x (velocity)2

         E=mgDh Potential Energy = mass x g x height change

         v=(2gh)

         W=Fd Work done = force applied x distance moved in direction of force

         Efficiency = (useful energy out)/(total energy in)

         P = Fv Rate of transfer (power) = force applied x velocity (if F & v constant)

         P=dW/dt

         FDt=Dmv Impulse = change in momentum OR force = rate of change of momentum

         F=dp/dt

         F=ma Force = mass x acceleration for constant mass

         pV=nRT pressure a 1/volume (n=moles, R=molar gas constant, T=temp)

         Fmax = mN Limiting value of frictional force = coefficient of friction x normal reaction force

 

Use (given on formula sheet):

              F = kx

              stress = tension/cross-sectional area

              strain = extension/original length

              Young modulus = stress/strain

              g = Fl/Ax

              elastic strain energy = kx2

              elastic strain energy per unit volume = stress x strain

              pV=1/3Nmc2 pressure x volume = 1/3 particles x mass of 1 particle x (average velocity)2

              p = 1/3 rc2 pressure p, density r, average velocity squared c2

              mean kinetic energy