A bus travels from west to east with a velocity of 11.5 m/s. A marble rolls on the surface of the bus floor with a velocity of 0.200 m/s north. What is the velocity of the marble relative to the road?

Answer 1

Use vectorial addition to add
Vb=(11.5,0) and Vm=(0,0.200)
The relative velocity of the marble with respect to the road is the sum of the vectors, add up the components to get Vr=(11.5,0.2).
The velocity is the magnitude of the resultant Vr. To determine the magnitude, see the example in:
http://www.jiskha.com/display.cgi?id=1253571803