A particle is moving in the +x direction at speed c/2. Another particle is moving in the -x direction at speed c/2 toward the first particle. what is the speed of one particle as seen by an observer moving with the other particle?

Observer S detects two flashes of light. A big flash occurs at x1 = 1271 m and, slightly later, a small flash occurs at x2 = 492 m. The time interval between the flashes is Δt = t2 - t1. What is the smallest value of Δt for which observer S' will determine that the two flashes occur at the same x' coordinate?

Two frames of reference A and B are in standard configuration with the origin of frame B moving along the x-axis of frame A at speed V, as measured in reference A. An observer in frame A detects an event with spatial coordinates: x1 = 10 × 108 m, y1 = 0 m, z1 = 0 m. After 3 seconds another event is detected in frame A, with spatial coordinates: x2 = 20 × 108 m, y2 = 0 m, z2 = 0 m. An observer in the frame of reference B observes the events happening simultaneously. What is the relative speed of the frames?

An observer in frame S′ is moving to the right (+x@direction) at speed u = 0.600c away from a stationary observer in frame S. The observer in S′ measures the speed v′ of a particle moving to the right away from her. What speed v does the observer in S measure for the particle if (a) v′ = 0.400c;       (b) v′ = 0.900c; (c) v′ = 0.990c

As the drawing shows, a carpenter on a space station has constructed a 30.0° ramp. A rocket moves past the space station with a relative speed of 0.535c in a direction parallel to side x. What does a person aboard the rocket measure for the angle of the ramp? Number i Units 30.0°

The space bus is 2.0 km long in its own frame and moves towards planet earth at a speed of 0.6c. Jim is on the bus while Carl is on earth. Jim is sitting at the back of the bus and launches a projectile towards the front of the bus at a speed of 0.4c. Ignore any acceleration times or energy considerations. (a) How fast does Carl measure the projectile to be moving? (b) How long does Carl measure the bus in his frame? (c) How long would Carl determine it would take for the projectile to reach the front of the bus?

Spaceships A and B are moving in the same direction along the same straight line. Spaceship A is moving at 0.800 c relative to a stationary observer, and spaceship B is moving at 0.800 c relative to spaceship A. What does the stationary observer find for the speed of spaceship B?

An Other Frame moves with a speed of 0.80 relative to the Home Frame. An object at rest in the Other Frame has a length of 30 ns as measured in the Home Frame. What is the object's length in the Other Frame?

Spacecraft I, containing students taking a physics exam, approaches the Earth with a speed of 0.660c (relative to the Earth), while spacecraft II, containing professors proctoring the exam, moves at 0.260c (relative to the Earth) directly toward the students. The professors stop the exam after 84.0 min have passed on their clock. (a) For what time interval (in minutes) does the exam last as measured by the students? min (b) For what time interval (in minutes) does the exam last as measured by an observer on Earth? 87.024 min What If? Suppose one of the professors proctored the exam by traveling on spacecraft I and stopped the exam after 84.0 min elapsed on her clock. (c) For what time interval (in minutes) does the exam last as measured by the professors on spacecraft II? min (d) For what time interval (in minutes) does the exam last as measured by an observer on Earth? min

A spaceship travels at a speed of 2.4 x 108 m/s. A clock in the spaceship passes 60 seconds. How much time (in second) passes on the clock at rest on the ground?