Over a time interval of 2.28 years, the velocity of a planet orbiting a distant star reverses direction, changing from +24.2 km/s to -16.2 km/s.
Find (a) the total change in the planet's velocity (in m/s) and
(b) its average acceleration (in m/s2) during this interval. Include the correct algebraic sign with your answers to convey the directions of the velocity and the acceleration.