An argon ion laser emits light of wavelength of 488 nm. (a) calculate the frequency of the light. (b) suppose a pulse of light from this laser is sent from earth, is reflected from a mirror on the moon, and returns to its starting point. calculate the time elapsed for the round trip, taking the distance from earth to the moon to be 3.8×10^5 km.

A) 6.15×10^14 per sec

B)2.5 sec

Explanation:

Wavelength of light = 488 nm

speed of light = 3×10^8 m/s

therefore, frequency of light  

⇒

⇒ν= 6.15×10^14 per sec

b) distance between moon and earth =  3.8×10^5 km.

= 3.8×10^8 m

light travel from earth moon and back to earth

therefore, distance traveled= 2× 3.8×10^8 m = 7.6×10^8 m

therefore time= distance/speed

⇒ time=

= 2.5 sec

So, for a round trip time required is 2.5 sec.

1.solid

2.carbon dioxide

3.helium

the answer is 1 i believe