A 1.5×103kg car travels due east at 20m/s while, on the same straight road, a 2.5×103kg truck travels due east at 10m/s. A 1.0×103kg motorcycle next to them is momentarily at rest. What is the magnitude of the total linear momentum of this three-vehicle system at that instant?
a) 4.0×104kg⋅m/s
b) 5.5×104kg⋅m/s
c) 2.5×104kg⋅m/s
d) 5.0×104kg⋅m/s