1- A spaceship,220m long as seen on board, moves relative to the Earth at0.79c.

Randomized Variables

l = 220 m v = 0.79 c

What is its length, in meters, as measured by an Earth-bound observer?

2- Consider a 6.1 m long sports car going past you at great speed.

How fast would it have to be going past you in order for it to appear only 5.6 m long? Give you answer as a ratio of the velocity to the speed of light c.

3- Suppose there is an astronaut who is traveling at a significant fraction of the speed of light.

Randomized Variables

d = 4.3 ly v = 0.84382 c

Part (a)How long, in years, does it take her to travel 4.3 ly at 0.84382c (as measured by the Earth-bound observer)?

Part (b)How long does it take according to the astronaut in years?

4- Suppose a spaceship heading straight towards the Earth at 0.75c can shoot a canister at 0.65c relative to the ship.

Part (a)If the canister is shot directly at Earth, what is the ratio of its velocity, as measured on Earth, to the speed of light?

Part (b)What about if it is shot directly away from the Earth (again, relative to c)?

5- Suppose the speed of light were only 3000.0 m/s. A jet fighter moving toward a target on the ground at 845 m/s shoots bullets, each having a muzzle velocity of 1150 m/s . Randomized Variables

v₁ = 845 m/s v₂ = 1150 m/s

What is the velocity of the bullets relative to the target in km/s?

6- Consider two spaceships moving relative to each other. The relative velocity of each spaceship is the velocity the other spaceship sees it moving at. Both relative velocities are equal in magnitude (equal speeds) but opposite in direction.

If one spaceship fires a missile at 0.755c at the other spaceship as it approaches and the other spaceship observes the missile approaching it at 0.94c, what is the ratio of the first spaceship's relative velocity to the speed of light? Assume the velocity toward the observer is considered positive.