http://asdpub.com/index.php/jam <p style="text-align: justify;">Journal of Advanced Mathematics (JAM) is monthly journal dedicated to publish articles from field of applied and pure mathmathatical sciences.</p> ASD Publisher en-US Journal of Advanced Mathematics <p>Authors who publish with this journal agree to the following terms:</p> <ol type="a"> <li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="http://creativecommons.org/licenses/by/3.0/" target="_new">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li> <li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li> <li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li> </ol> http://asdpub.com/index.php/jam/article/view/385 <p>In the first section of the paper a rocket powered aircraft is constrained to fly in a rectilinear path of a very small inclination with respect to the horizon by exerting necessary thrust control .For such a typical maneuver, velocity-time, velocity-altitude and velocity- horizontal distance distributions have been established. Final payload ratio is also found .In the second section the aircraft is maneuvered with constant velocity along a rectilinear path of the same nature which calls for continuous variation of both angle of attack and thrust and the dimensionless thrust is found to obey exponential law with respect to time. In the third section of the paper&nbsp; is considered that the vehicle moves with constant dynamic pressure, which also entails continuous variation of the thrust and angle of attack .Either of lift coefficient and pay load ratio is found to satisfy a linear differential equation which can be solved by approximate-procedures depending on the values of drag and lift coefficient. In each section a parabolic drag with constant coefficients is considered and the load factor is maintained equal to the unity to yield a rectilinear path.</p> Soumen N. Maitra ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2018-12-05 2018-12-05 4 3 10 12 http://asdpub.com/index.php/jam/article/view/386 <p>In this paper is first found out the approximate altitude attained by the spacecraft in vacuum at any time after it is subjected to a constant radial thrust acceleration in vacuum, i.e., a variable thrust designated by constant thrust-to- weight ratio in the radial direction. The mass-variation law due to propellant consumption and the trajectory of the spacecraft in elliptic integral form in the neighborhood of the Earth &nbsp;and thereafter in normal integral form with sufficient accuracy are determined.</p> Soumen N. Maitra ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2018-12-05 2018-12-05 4 3 13 14