Question

A spaceship leaves a space station and emits a flash of light that travels at a speed of 300,000 km/s. The spaceship starts out travelling at 1/4 the speed of light, but ends up travelling at 99/100 the speed of light. What does a scientist on the space station measure the speed of the flash to be?

B. (1/4) x 300, 000 km/s

C. (1/100) x 300, 000 km/s

D. 300, 000 km/s

Answer 1

@hartnn

Answer 2

@.Sam.

Answer 3

@KeganMoore

Answer 4

A. how did he measure the speed of light?

Answer 5

I got something, Speed of light is same with respect to any frame of reference. I was a bit confused by the fact that the observer is moving at a speed of 0.99 C
But it'd be still the same. Please see the below link :

Answer 6

http://www.einstein-online.info/elementary/specialRT/speed_of_light

Answer 7

so its D

Answer 8

Right, same speed irrespective of the frame of reference of observer

Answer 9

What's the question?

Answer 10

In general relativity, gravitational red shift is caused by

A. the slowing of clocks due to increased gravitational kinetic energy.

C. the slowing of clocks due to lower gravitational kinetic energy.

D. the slowing of clocks due to lower gravitational potential energy.

Answer 11

is it D

Answer 12

How do you say D?

Answer 13

Gravitational red shift is the process by which electromagnetic radiation originating from a source that is in gravitational field is reduced in frequency, when observed in a region of a weaker gravitational field. This is as a direct result of Gravitational time dilation, frequency of the electromagnetic radiation is reduced in an area of a lower gravitational potential.

Answer 14

yes, then it could be D. thanks

Answer 15

but can you please confirm it

Answer 16

You are communicating with aliens on Jupiter and Saturn. When you send a light beam message to your friend on Jupiter and receive a message from your friend on Saturn, you realize that the light messages became curved when they passed by the sun. What would be the sum of the angles in the triangle formed by the paths your messages take?

A. 0 degrees

C. 180 degrees

D. a number larger than 180 degrees

Answer 17

@ash2326

Answer 18

@LilySwan Sorry I have no idea about this

Answer 19

i think its C

Answer 20

light travels in straight line

Answer 21

One way that astronomers detect planets around distant stars is by observing to see if there is a _________ in the light that reaches us from a particular star. The reason that the star moves away or toward us is a ________ due to the gravitational effects of the planet.

B. Doppler shift, contraction

D. Doppler shift, perturbation

Answer 22

@LilySwan Please post new questions as a new post, that way more people will answer it