A spaceship leaves Earth traveling at 0.70c. A second spaceship leaves the first at a speed of 0.90c with respect to the first. Calculate the speed of the second ship with respect to Earth if it is fired in the same direction the first spaceship is already moving. Express your answer using two significant figures. [ΕΙ ΑΣΦΑ V= Submit Part B Request Answer U= → C ? Calculate the speed of the second ship with respect to Earth if it is fired directly backward toward Earth. Express your answer using two significant figures. IVE ΑΣΦΑ → C ? C

A starship moves away from Mars at a speed of 0.75c relative to Mars. The starship launched a small rocket with the length of 13 m as measured by an observer on the starship. The small rocket moves in the same direction as the starship at a speed of 0.40c relative to the starship. i) Find the velocity of the small rocket relative to Mars.ii) Calculate the length of the small rocket as measured by an observer on Mars.

A friend speeds by you in her spacecraft at a speed of 0.790 c. It is measured in your frame to be 4.60 m long and 1.60 m high. Part A What will be its length at rest? lo = 7.50 m Submit ✓ Correct Correct answer is shown. Your answer 7.49 m was either rounded differently or used a different number of significant figu Part B What will be its height at rest? ho= 2.61 Submit Previous Answers Request Answer Part C Previous Answers X Incorrect; Try Again; 4 attempts remaining Submit Part D IVE ΑΣΦ How many seconds elapsed on your friend's watch when 23.0 s passed on yours? Ato 14.1 s Submit Part E ✓ Correct Important: If you use this answer in later parts, use the full unrounded value in your calculations. Ato = Previous Answers How fast did you appear to be traveling according to your friend? OF [Π ΑΣΦ Submit ? Request Answer m How many seconds elapsed on your watch when she saw 23.0 s pass on hers? ■ | ΑΣΦ Request Answer ? S

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.