## speed of light and velocity

$c=\lambda v$

Savannah Mance 4G
Posts: 107
Joined: Fri Aug 30, 2019 12:17 am

### speed of light and velocity

I've seen the speed of light equation also be written with velocity in place of c. Are velocity and speed always used interchangeably or is it only for speed of light because light only travels in one direction?

Midori Hupfeld 3D
Posts: 55
Joined: Fri Aug 30, 2019 12:17 am

### Re: speed of light and velocity

Velocity is speed with direction, so they cannot be used interchangeably if you need to convey direction or not. The speed of light is a constant and I don't think that you can really determine the direction of light.

William Chan 1D
Posts: 102
Joined: Sat Sep 14, 2019 12:15 am

### Re: speed of light and velocity

Velocity and speed are often used interchangeably. None of the calculations we make in this class will necessarily require us to know the direction of light, so we just focus on the speed instead.

Eugene Chung 3F
Posts: 142
Joined: Wed Nov 15, 2017 3:03 am

### Re: speed of light and velocity

in terms of calculations in this class, I believe it doesn't matter. But, it would help a lot in the future to know that they are two different concepts for Physics.

gferg21
Posts: 51
Joined: Sat Aug 17, 2019 12:17 am

### Re: speed of light and velocity

because velocity has a speed of 3 x10^8 m/s, it is often used interchangeably with velocity because some equations need the speed of light. However, the direction of light is not specified with light.

Aarushi Solanki 4F
Posts: 107
Joined: Sat Jul 20, 2019 12:17 am

### Re: speed of light and velocity

"c" (speed of light) can never be replaced by "v" (velocity) because "c" is a constant which is known and "v" is a variable which is unknown.

Caitlin Ciardelli 3E
Posts: 44
Joined: Wed Sep 18, 2019 12:19 am

### Re: speed of light and velocity

It is important to remember that speed of light is a constant and velocity is not a constant!
c=3.00x10^8 m/s

Equally important to remember, that speed of light equals wavelength times frequency
c= (lamda)v= 3.00x10^8 m/s