This rapid action revision, dated 19 December 2006--. o Updates the terminology for Army major commands and headquarters. (throughout). o Clarifies that unit commanders are solely responsible for the accuracy of the. information and data they enter into their reports (paras 1-1 and D-1).
A 400g model rocket is on a cart that is rolling to the right at a speed of 4.0m/s. The rocket engine, when it is fired, exerts an 7.0 N thrust on the rocket. Your goal is to have the rocket pass through a small horizontal hoop that is 15m above the launch point. At what horizontal distance left of the loop... show more A 400g model rocket is on a cart that is rolling to the right at a speed of 4.0m/s. The rocket engine, when it is fired, exerts an 7.0 N thrust on the rocket. Your goal is to have the rocket pass through a small horizontal hoop that is 15m above the launch point.
Best Answer: Time of flight t = 2vy/g Distance = vx*t = 2vx*vy/g We must maximize vx*vy as a function of launch velocity v. vx = vcosÎ¸, vy=vsinÎ¸ Thus we must maximize sinÎ¸cosÎ¸. At the maximum, the derivative of sinÎ¸cosÎ¸ = 0. From the ref, the derivative = cos(2Î¸).Thus cos(2Î¸) = 0, 2Î¸ = 90 deg, Î¸ = 45 deg.'d put optimal at a lower angle, say 20 to 30 degrees, to keep most of the air time while reducing the energy lost at landing and improving the horizontal speed component for the post-landing roll.