They both go in the same direction away from you. How fast is the missile going in relation to you?
2007-12-23 03:36:09 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The most correct way to add velocities is to use the relativisitc transformation of velocities; but at speeds of 1% the speed of light, relativistic effects are still minor. But, the full analysis shows:
call v(my)=speed of missile with respect to you
call v(mr) = speed of missile with respect to rocket
call v(ry) = speed of rocket with respect to you
then:
v(my) = [v(ry)+v(mr)] divided by [1+(v(ry)v(mr)]/c^2]
v(my)=
[6x10^6 m/s]/[1+(9x10^12/9x10^16)]
=6x10^6/1.0001] or a number slightly less than 6x10^6, the number you get from the simple Galilean transformation of velocities (just adding them up)
2007-12-23 04:33:22 · answer #1 · answered by kuiperbelt2003 7 · 2⤊ 1⤋
If I'm on the ship then the missile looks like it is moving 3 million m/s.
If I'm on the ground, the missile looks like it is moving 6 million m/s away from me and the ship is moving 3 million m/s away from me.
This is called your reference frame in physics. We use reference frames to describe the motion of an object with respect to another object.
If you standing on the Earth and looking at the Sun, you would say the Sun is moving but if you in space looking at the Sun and the Earth you would say the Earth is moving and if you were in space outside the Solar System they you would say the Earth and Sun would be moving.
2007-12-23 03:41:48 · answer #2 · answered by Anonymous · 1⤊ 2⤋
Err, no to all of the above. You are neglecting Lorentz contraction. sqrt(1 - v^2/c^2). If the spaceship were receding at 0.75c and it fired a missile at 0.75c relative to its frame of reference we'd hardly say the missile was receding from us at 1.5c, would we? The answer in our case is we measure the missile as receding from us at about 5.9988 x 10^6 m/s.
2007-12-23 04:10:54 · answer #3 · answered by David G 6 · 2⤊ 1⤋
3 million m/s
2007-12-23 03:40:36 · answer #4 · answered by Anonymous · 0⤊ 1⤋
The missile will be traveling at 6million miles/s away from you, if viewed from an observer on Earth, but it will be traveling at 3million miles/s away from you, if viewed from an observer on the space ship.
2007-12-23 03:48:57 · answer #5 · answered by TicToc.... 7 · 0⤊ 1⤋
6 million m/s away from you
2007-12-23 03:38:58 · answer #6 · answered by Dr D 7 · 2⤊ 2⤋