At an antique car rally, a Stanley Steamer automobile travels north at 38 km/h and a Pierce Arrow automobile travels east at 51 km/h. Relative to an observer riding in the Stanley Steamer, what are the x- and y-components of the velocity of the Pierce Arrow car?

Answer 1

V of pa relative to ss
+ V of ss relative to ground
= V of pa relative to ground

Therefore (using an abbreviated notation)

Vpa/ss = Vpa/g - Vss/g
= 51 i - 38 j

i is a unit vector east and j is a unit vector north.

The x component is 51 km/h and the y component is -38