Physics

Physics

1. Stress&Strain

   • Stress= Force (N) / X-sectional area
     • Stress = k x Strain
   • Strain = extension/original length
     • Hooke's Law= extension proportional to force

2. Density&Pressure

   • Density: Mass / Volume
   • Pressure = Force/ Base Area

3. Momentum

   • Momentum = Mass x Velocity
   • Initial velocity = final velocity
     • Elastic
       • M1V1 + M2V2 = M1U1 + M2U2
     • Inelastic
       • M1U1 + M2U2 = (M1 + M2)V
     • Coeff of restitution
       • V1 - V2 = -e (M1 - M2)
   • Force: Change in momentum / time

4. Moments

   • Force x perpendicular distance
   • Classes of levers
   • Mechanical advantage = Load/effort
   • Velocity Ratio: Distance effott/distance load
     • Mechanical effieciency: output/input x100
       • Ma/eff x 100

5. Forces and Movement

   • Force = Mass x A
   • Air resistance
     • terminal V: Mg = Fd, a=0
   • Mew = Fn/R