A probe moves in a straight line through deep space, starting from rest at the origin at t=0. For 0≤t<4s the probe experiences constant acceleration 2m/s2 in the +x direction; for 4≤t<8s its acceleration is 0; and for 8≤t≤12s its acceleration is −1m/s2 (opposite the +x direction). What is the probe’s position relative to the origin at t=12s?
a) 56m
b) 64m
c) 72m
d) 40m