During a thunderstorm, an observer notes that 10 s elapsed ...

[mckennatimberlake]

During a thunderstorm, an observer notes that 10 s elapsed between the lightning flash and the sound of the thunder. What is the approximate distance, in miles, from the observer to the lightning?

Question 2

A helium-neon laser emits red light having a wavelength of 6.4  107 m and a power of 0.5 mW. How many photons are emitted each second?
 a. 6.4  1038
  b. 1.6  1021
  c. 3.2  1025
  d. 2.6  1018
  e. 1.6  1015

[Juro]

Answer to Question 1

2 mi

Answer to Question 2

e

[mckennatimberlake]

Excellent

[xiaomengxian]

Thanks for the timely response, appreciate it