A rocket-propelled sled moves along a horizontal track. At t=0 the sled is already moving toward the +x direction with a speed of 15 m/s. From t=0 to t=4.0s the rockets generate a constant acceleration of 5.0 m/s2 in the +x direction. Immediately afterward (t=4.0s) the rockets shut off and a parachute deploys, producing a constant acceleration of –3.0 m/s2 until the sled comes to rest.
Assume the track is level and friction is negligible except for the forces described above.
(a) Determine the sled’s speed immediately after the rockets shut off at t=4.0s.
(b) Calculate the additional time required for the sled to come to rest after the parachute deploys.
(c) Determine the sled’s displacement during the powered (rocket) phase.
(d) Determine the sled’s displacement during the parachute phase.
(e) On axes that have been provided in your answer booklet, sketch a graph of velocity vx versus time for the entire motion from t=0 until the sled stops. Clearly label numerical values for velocity and time at all key points found in parts (a) and (b).