# Physics

posted by
**Katie**
.

Bob and Bob Jr. stand at open doorways at opposite ends of an airplane hangar 25 m long. Anna owns a spaceship, 40 m long as it sits on the runway. Anna takes off in her spaceship, then swoops through the hangar at constant velocity. At precisely time zero on both Bob's clock and Anna's, Bob sees Anna at the front of her spaceship reach his doorway. At time zero on his clock, Bob Jr. sees the tail of Anna's spaceship at his doorway.

A) How fast is Anna's spaceship moving?

v/c = 0.781

B) What will Anna's clock read when she sees the tail of her spaceship at the doorway where Bob Jr. is standing?

1.04 x 10^-7 s

C) How far will Anna say the front of her spaceship is from Bob at this time?

24.375 m

I'm extremely confused. I know d = vt. Then, t = d/v but v is not given and I was thinking about using c, 3 x 10^8 m/s. Any help is greatly appreciated, thank you