If a person lives on the average 100 years in his rest frame, how long does he live in the earth frame if he spends all his life in a spaceship going at 60% of the speed of light .

Five years ago, the age of a person was half of his present age. How old is he now ?

The person lived near a forest. Make a list of four items which he can get from the forest to meet his daily needs.

A person goes to his office at 1/3rd of the speed at which he returns from his office. If the average speed during the whole trip (i.e., one round) is 12 km/h. What is the speed of the person while he was going to his office?

As the earth rotates about its axis, a person living in his house at the equator goes in a circular orbit of radius equal to the radius of the earth. Why does he/she not feel weightless as a satellite passenger does?