Imagine that you are located on Earth while a spaceship travels from Earth to the star Vega at constant velocity of 0.8c.
The following items describe quantities that, according to Einstein’s special theory of relativity, would be either larger (or longer), smaller (or shorter), or the same as their rest values. (Note that by "rest value," we mean the value you would find if both you and the spaceship were at rest on Earth.)

Match each item to the correct category.

1) one second on your clock as seen by spaceship passengers
2) one second on a spaceship clock as seen by you
3) speed of the spaceship's headlight as measured by you
4) mass of spaceship as measured by you
5) distance to Vega as measured by spaceship passengers
6) length (in the direction of motion) of the spaceship as measured by you
7) your mass as measured by spaceship passengers