A small research rocket is launched vertically upward from rest
MATHEMATICS · Multi-part · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation
Problem
A small research rocket is launched vertically upward from rest. The acceleration profile (positive upward) is described verbally below.
• From t=0s to t=4s, the upward acceleration increases linearly from 0 to +12m/s2.
• From t=4s to t=8s, the acceleration decreases linearly to −4m/s2 (the engines throttle down past zero to provide a small downward thrust).
• From t=8s to t=12s, the acceleration remains constant at −4m/s2.
• At t=12s the engines shut off completely, after which the only acceleration is gravitational: −9.8m/s2 (assumed constant).
Ignore air resistance throughout.
(a) Determine the rocket’s velocity at t=4s and at t=8s.
(b) Identify the rocket’s maximum upward velocity attained during the first 12s of flight and state the time at which it occurs.
(c) Calculate the rocket’s altitude (vertical displacement relative to the launch point) at t=12s.
(d) After engine cutoff, determine (i) the additional time required for the rocket to reach its highest point and (ii) that maximum altitude above the launch point.