Question

Car 1 drives 20mph to the south and car 2 drives 30mph to the north. From the frame of reference to car 1 what is the velocity of car 2?

Answer 1

To a Physics student riding in Car-1 and carrying

his frame of reference with him, he measures the

velocity of Car-2 to be 50 mph to the north.

Answer 2

The difference in velocity between it and car 2, which is 30-20=50 mph south