Question

You are traveling in a spaceship at a speed of 0.70c away from Earth. You send a laser beam toward the Earth traveling at velocity c relative to you.

What do observers on the Earth measure for the speed of the laser beam?

Answer 1

I thought the answer to this would be the same because speed of light is the same for everyone but it is wrong and I dont know where I went wrong in this

Answer 2

Surely we all measure c as you said.

Answer 3

I dont get it how this cant be 0.70c

would i multiply it by the constant 3.0x 10^8 (0.70c)

Answer 4

we would measure the speed c =3.0 x 10^8

Answer 5

as an observer

Answer 6

that is also wrong, because it gives a hint saying v = ___________ c the c is a unit, I am not sure where I am going wrong

Answer 7

without acceleration in a vacuum light has the same speed irrespective of relative velocities. It is always c. C is also not a unit. its maybe asking for a multiple of c, which would be 1 x c

Answer 8

ohh, so I would multiply the constant by 1 and I would get 3.0*10^9

Answer 9

I think so, did it work?

Answer 10

no it did not

Answer 11

actually it says v= __________ x c I didnt see the dot it was very tiny

Answer 12

ahh cool, got to be 1 x c

Answer 13

oh so the velocity is 1 x c ..thats it? how is that possible

Answer 14

the speed of light is always c in a vacuum. its a consequence of maxwells equations (which i dont understand). Time and space have to bend/distort in order to allow all people to view light with speed c. its pretty incredible

Answer 15

ohhhh, Thank you very much