Linear motion with variable acceleration

Linear Motion with Variable Acceleration

Basic Concepts

  • Linear motion refers to the motion of an object along a straight line.
  • Variable acceleration signifies that the rate of change of velocity is not constant.
  • This concept ties into the fundaments of calculus and requires the use of integration and differentiation.

Variable Acceleration

  • The change in velocity, also known as acceleration, is the derivative of velocity with respect to time (a = dv/dt).
  • Variable acceleration means this rate of change is not constant, therefore the acceleration function will be a function of time, a = a(t).
  • The change in position, or displacement, is the integral of velocity over time.
  • Velocity can be expressed as the integral of acceleration over time plus an initial velocity (v = ∫a dt + u), where ‘u’ is the initial velocity (at t = 0).

Kinematic Equations

  • By integrating the acceleration function, you can obtain the velocity-time equation.
  • Similarly, by integrating the velocity function, you can obtain the displacement-time equation.
  • These equations can then be used to find out the final position, velocity or acceleration at any given time.

Practical Calculation Steps

  • Write down the given acceleration function, initial velocity and initial position.
  • Integrate the acceleration function to find the velocity function. Remember to include the ‘plus C’ constant of integration, which can be determined using initial conditions.
  • Integrate the velocity function to find the displacement function.
  • Use these equations to find the values of your position, velocity, and acceleration at any desired time.

Application of the Principles

  • Understanding linear motion with variable acceleration is useful in physics, engineering and any field where modelling the movement of objects is important.