AS edexcel Summary

Projectile Motion

  • Projectile Types: Distinction between horizontal and vertical projectiles.

    • Horizontal Projectile Motion:

      • Velocity (V) = Displacement/Time

      • Horizontal velocity (Vx) remains constant: S = Vx * t

    • Vertical Projectile Motion:

      • Acceleration (a) = -9.81 m/s² (due to gravity)

      • At maximum height, velocity (V) = 0

Kinematic Equations

  • Common quantities in projectile motion include time.

  • Relevant equations:

    • V = u + at

    • V² - U² = 2as

    • S = ut + (1/2)at²

Viscosity and Laminar Flow

  • Viscosity: Resistance of a fluid to flow.

  • Laminar Flow:

    • Characteristics:

      • Low velocity

      • Shape impact on flow

      • Spherical shape particles.

  • Falling Sphere:

    • When falling at constant velocity, net force = 0 (Upward force = Downward force).

  • Forces Involved:

    • Drag Force (FD) = 6πrηv , where η is viscosity, r is radius, v is velocity.

Work and Energy

  • Work (W): Work = Force x Distance (in the direction of force).

    • Example Calculation: W = 10N * 5m = 50 J.

  • Kinetic Energy (KE):

    • KE = (1/2)mv²

  • Gravitational Potential Energy (GPE):

    • GPE = mgh

  • Elastic Potential Energy (EPE):

    • EPE = (1/2)Fx or EPE = (1/2)kx²

  • Energy Loss: Some energy is lost due to heat from friction during loading and unloading of elastic materials.

Elasticity and Hooke's Law

  • Elastic Material: Returns to its original shape; may not obey Hooke's law if the graph is not a straight line.

  • Young’s Modulus:

    • Stress = Force/Area

    • Strain = Change in Length/Original Length

Moment and Torque

  • Moment (Torque):

    • Moment = Force x Perpendicular distance from pivot

  • Rotational Equilibrium: A.C.W (anticlockwise) moments equal C.W (clockwise) moments.

Momentum and Collisions

  • Momentum (p):

    • Momentum = mass x velocity (p = mv)

    • Collision equations:

      • m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

  • Newton's Laws of Motion:

    • 2nd Law: Force = rate of change of momentum (F = m(v-u)/t)

    • 3rd Law: For every action, there is an equal and opposite reaction.