~ Need PHYSICS/HOMEWORK HELP! ~ (PLEASE!)

I have a few physics questions and they have got me stuffed. if someone could help and justify there answer thanks

1) A spaceship travels with a speed of 0.7c as it passes the earth on its way to a distant star. The pilot of the spaceship measures the length of the moving ship as 30m

Determine its length as measured by a person on earth. Answer units in m.

2) (Extension of question 1) - The pilot of the spaceship observes that the spaceship travels for 9 years.

Determine how much time has passed according to a person on earth. Answer in units of years

3) (extension of question 1 & 2) Some time after the passing of earth, the pilot shoots a laser pulse backwards at a speed of 3*10^8 m/s (3 times 10 to the power of 8 meters per second) with respect to the spaceship.

Determine the speed of the laser pulse as measured by a person on earth. Answer in units m/s





Thanks Very Much

 

Answered the first question on the other thread already, you don't need to post this up everywhere.

 

Thanks, its just i noticed that physics is usually on this page so i posted here als. its due tonight and i need help!