Kinematics of Particle (KOP) - General Questions (5)

A two-stage missile is fired vertically from rest with an acceleration as shown in the graph. In 15 s the first stage A burns out and the second stage B ignites. How fast is the rocket moving and how far has it gone at t = 20 s? How fast is the missile moving and how far has it gone at t = 20 s?

A race car starting from rest moves along a straight track with an acceleration as shown in the graph (where for t  10 s, a = 8 m/s²). Determine the time t for the car to reach a speed of 50 m/s.