Two Dogs,Rover and Fido,run on a Level Frictionless Surface

Multiple Choice

Two dogs,Rover and Fido,run on a level frictionless surface.Rover runs eastward with a momentum of 24 kg .m/s,and Fido runs northward with momentum 10 kg .m/s.They make a sudden perfectly inelastic collision.What is the magnitude of their combined momentum after the collision?

A) 14 kg .m/s
B) 26 kg .m/s
C) 34 kg .m/s
D) It cannot be determined without knowing the masses and velocities of the dogs.