Question

Part A

A laser used to dazzle the audience at a rock concert emits red light with a wavelength of 697 nm . Calculate the frequency of the light.

Express your answer with the appropriate units.

Part B

X-rays pass through many substances that block visible light and are therefore used to image bones and internal organs. Which of the following is a correct statement about X-rays?

X-rays have higher frequency than visible light.

X-rays have longer wavelength than visible light.

X-rays have lower energy than visible light.

X-rays have lower frequency than visible light.

Part C

Place the following types of electromagnetic radiation in order of increasing wavelength.

ultraviolet light microwaves gamma rays

microwaves < ultraviolet light < gamma rays

gamma rays < ultraviolet light < microwaves

microwaves < gamma rays < ultraviolet light

gamma rays < microwaves < ultraviolet light

ultraviolet light < gamma rays < microwaves

Answer 1

A)

Given:

lambda = 6.97*10^-7 m

use:

f = c/lambda

=(3.0*10^8 m/s)/(6.97*10^-7 m)

= 4.304*10^14 Hz

Answer: 4.30*10^14 Hz

B)

X ray have higher energy and hence higher frequency than visible light

This also implies, X ray has lower wavelength than visible light

Answer: X-rays have higher frequency than visible light.

C)

microwaves of least energy and hence maximum wavelength

gamma rays of highest energy and hence least wavelength

gamma rays < ultraviolet light < microwaves