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Mechanics

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The case of constant acceleration and motion in a straight line yields some simple equations that permit the evaluation of the velocity and position of the vehicle if the initial conditions are known.

From the definition
(dv/dt) = a, the velocity at a later time t can be determined from the initial velocity, v(0), and the constant acceleration, a, by integration. This gives: v(t) = v(0) + at.

From the definitions:
v = (ds/dt) and a = (dv/dt) it is seen that dt = (ds/v) = (dv/a) so that v dv= a ds. Integrating this expression for motion between locations s = 0 and s gives: v(t)2 = v(0)2 + 2as.

Substituting the expression for v(t) into the definition of velocity and integrating relates the position at any time, t, to the initial velocity, v(0), and the constant acceleration, a:
s(t) = v(0)t + at2/2.