Apolice officer is driving due north at a constant speed of 29 m/s rel- ative to the ground when she notices a truck on an east–west highway ahead of her, driving west at high speed. she finds that the truck’s speed relative to her car is 48 m/s (about 110 mph). (a) sketch the vector trian- gle that shows how the truck’s velocity relative to the ground is related to the police car’s velocity relative to the ground and to the truck’s veloc- ity relative to the police car. the sketch need not be to scale, but the ve- locity vectors should be oriented correctly and bear the appropriate labels. (b) what is the truck’s speed, relative to the ground?