Professor Einstein is standing on a space station and observes two spaceships approaching him fromopposite directions at speeds of 0.8c and 0.7c. What is the speed of one spaceship moving withrespect to the other?

A 1 km spacecraft is racing towards the Sun at 0.75c. Using equations given in class, calculate the spacecraft length you measure from Earth. Treat Earth as not moving compared to the spacecraft's motion of 0.75 c.

What is the momentum of a proton moving at a speed of v = 0.75c?

A person on earth notices a rocket approaching from the right at a speed of 0.71c and another rocket approaching from the left at 0.66c. What is the relative speed between the two rockets, as measured by a passenger on one of them? Number VLE Earth's rest frame Units VRE ◄►

A UFO streaks across a football field at 0.90c relative to the goal posts. Standing on the field, you measure the length of the UFO to be 228 m. The UFO later lands, allowing you to measure it with a meter stick. What length do you now obtain?

A person on earth notices a rocket approaching from the right at a speed of 0.79c and another rocket approaching from the left at 0.55c. What is the relative speed between the two rockets, as measured by a passenger on one of them?

A very fast-moving train car passes you, moving to the right at 0.50c. You measure its length to be 12 m. Your friend David flies past you to the right at a speed relative to you of 0.80c. How long does David measure the train car to be?

A particle is created in the upper atmosphere; 18km above the surfaceof the Earth as measured by someone on the ground. The particle travelstowards Earth’s surface at a speed of 0.95c as measured by someone on theground. The particle travels for a time period 2.0 × 10−5s as measured inthe particle’s rest frame. The question is attached as an image and the correct answer is A, could someone please explain why this is

A particle known as a pion lives for a short time before breaking apart into other particles. Suppose a pion is moving at a speed of 0.990c, and an observer who is stationary in a laboratory measures the pion's lifetime to be 2.6 × 10-8 s. (a) What is the lifetime according to a hypothetical person who is riding along with the pion? (b) According to this hypothetical person, how far does the laboratory move before the pion breaks apart? (a) Number i (b) Number i Units Units

An astronaut on a space station is moving away from earth at 0.6 c. A spacecraft mannedby a different astronaut is heading towards him in the direction of earth at 0.6 c relative to the space station.Mission control sits on earth and observes both crafts. The first astronaut watches a film in his space station.All three observers time how long the film takes. Who measures the film’s proper time?