At the start of the flight, when the velocity of the rocket is zero, the ejected exhaust is moving to the left, relative to our coordinate system, at 2400 m/s. at the end of the first second, the rocket is moving at 40 m/s. the speed of the exhaust relative to our system is 2360 m/s. we could now compute the acceleration at t=1.0 s (using the decreased rocket mass), find the velocity at t=2.0 s, and so on, stepping through the calculation one second at a time until all the fuel is used up. as the mass decreases, the acceleration in successive 1 s intervals increases. a. find the rocket velocity after 2 seconds of launchb. find the rocket veloctiy after 3 seconds of launch.

Abasketball star covers 2.65 m horizontally in a jump to dunk the ball. his motion through space can be modeled precisely as that of a particle at his center of mass. his center of mass is at elevation 1.02 m when he leaves the floor. it reaches a maximum height of 1.90 m above the floor and is at elevation 0.910 m when he touches down again. (a) determine his time of flight (his "hang time"). (b) determine his horizontal velocity at the instant of takeoff. (c) determine his vertical velocity at the instant of takeoff. (d) determine his takeoff angle. (e) for comparison, determine the hang time of a whitetail deer making a jump with center-of-mass elevations yi = 1.20 m, ymax = 2.45 m, and yf = 0.750 m.