Cindy and Roy are living together. Cindy went out to buy food at a speed of v, while Roy was playing games at home. Cindy wears her watch when she went out, if it takes Cindy twice as long to reach the park as measured by her watch, compared to Roy's home clock, at what speed is she moving? Assuming that sports watches and home clocks are ideal clocks. When Cindy arrived at the restaurant, Roy stopped playing games.

(a) Draw the spacetime diagram for these events, indicate the time when Cindy arrived in both her watch and Roys home clock

(b) When does Roy stopped playing the game? Before, after, or simultaneously when Cindy arrived at the restaurant? Indicating both the time read from Cindys watch and Roys home clock (dont need numerical values).

(c) How far is the restaurant from Roy? How far is it from Cindy when she set off from home.

(d) According to Roy's home clock and Cindy's watch, how long does it take Roy to stop playing games? what is Roy s position in Cindy's reference frame?

(e) Suppose that when Cindy wants to called Roy and asked him what to eat, so that Roy just stopped playing the game when she arrived at the restaurant and answered the phone call. According to Cindy's reference frame, at what time does she need to send the phone signal, according to her watch.