# An observer measures the length of an object. In which of the following cases is the measured length at a minimum?

Choose one answer.

a. The observer and the object move with the same speed v in the same direction.

b. The observer and the object move with the same speed v in the opposite direction.

c. The observer and the object move with the same speed v in perpendicular directions.

d. The observer moves at an angle 30° to the direction of the object, but both move with the same speed.