Kinematics - Maximum and Minimum Motion Quantities

Kinematics - Maximum and Minimum Motion Quantities

    A particle moves in a straight line so that, \(t\) seconds after passing through a fixed point \(O\), its velocity \(v\) ms\({}^{-1}\), is given by \(v=3e^t-40e^{-2t}\). Find

    1. the initial velocity of the particle.
    2. the value of \(t\) when the particle is instantaneously at rest.
    3. the acceleration of the particle when \(t=\ln 2\).
    4. the value of \(t\) when the acceleration is minimum.
    5. an expression for the displacement in terms of \(t\).

    Video Solution:

    Video Solution

    Video solution locked

    A free account saves your progress; this video needs a course plan.

    Solution:

    Solution locked

    680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

    Answer:(a) \(-37\text{ m s}^{-1}\). (b) \(t=\frac13\ln\frac{40}{3}=0.863\) s. (c) \(26\text{ m s}^{-2}\). (d) Minimum acceleration at \(t=\frac13\ln\frac{160}{3}=1.33\) s. (e) \(s=3e^t+20e^{-2t}-23\).

    Need help? Join our A-Maths tuition classes.

    Learn more