You are viewing an old version of this page. View the current version.

Compare with Current View Page History

Version 1 Next »

Integration of the Definitions in Special Cases

The defnitions of the acceleration and velocity can be integrated, provided something is known about the functional form of the acceleration. The general procedure is to first find the velocity as a function of time by integrating the acceleration:

Unknown macro: {latex}

\begin

Unknown macro: {large}

[ \int_{v_{i}}^

Unknown macro: {v}

dv = \int_{t_{i}}^

Unknown macro: {t}

a\:dt]\end

and then use that velocity in the integral:

Unknown macro: {latex}

\begin

Unknown macro: {large}

[ \int_{x_{i}}^

Unknown macro: {x}

dx = \int_{t_{i}}^

Unknown macro: {t}

v\:dt ]\end

Two basic forms of the acceleration are widely useful and so we illustrate the procedure for these as special cases.

Constant Acceleration

If the acceleration is constant then the velocity has the form:

Unknown macro: {latex}

\begin

Unknown macro: {large}

[ v - v_

Unknown macro: {i}

= a(t-t_

) ]\end

which is substituted into the next integral to find:

Unknown macro: {latex}

\begin

Unknown macro: {large}

[ x - x_

Unknown macro: {i}

= \int_{t_{i}}^

Unknown macro: {t}

\left(a(t-t_

)+ v_

Unknown macro: {i}

\right)\:dt = v_

(t-t_

Unknown macro: {i}

) + \frac

Unknown macro: {1}
Unknown macro: {2}

a(t-t_

)^

Unknown macro: {2}

]\end

This equation is the basic Law of Change for the [One-Dimensional Motion with Constant Acceleration] model.

Does this agree with the Law of Change for One-Dimensional Motion with Constant Velocity for the special case a = 0?

  • No labels