Gamora flies her spacecraft in the +x-direction past the planet Xandar at 0.750c while her sister Nebula is at rest on the surface of the planet. As Gamora passes Nebula, both sisters set their clocks to zero. Each chooses the zero of the x-axis to be at her position. (a) Nebula sets off fireworks next to her 2.50 s after Gamora passes her. What are the coordinates of this event as measured by Gamora? (b) Gamora detects an explosion in space that occurs 4.00 x 108 m in front of her 2.50 s after she passes Nebula. What are the coordinates of this event as measured by Nebula?