1. What is true about X-rays and microwaves?
a. X-rays have greater speed than microwaves.
b. X-rays have greater amplitude than microwaves.
c. X-rays have greater frequency than microwaves.
d. X-rays have greater wavelength than microwaves.
2. The wavelength of a longitudinal wave is the distance from,
a. compression to rarefaction.
b. compression to compression.
c. crest to trough.
d. crest to crest.
3. What is one reason sound travels faster in liquid water than in air?
a. Air molecules are less elastic than liquid water molecules because air molecules have weaker attractions.
b. Air molecules are more elastic than liquid water molecules because air molecules have weaker attractions.
c. Air molecules are more elastic than liquid water molecules because air molecules have stronger attractions.
d. Air molecules are less elastic than liquid water molecules because air molecules have stronger attractions.
1. c
2. a
3. d
Correct!
To determine the correct answers to these questions, we can analyze the properties of X-rays and microwaves, longitudinal waves, and the factors affecting the speed of sound.
1. What is true about X-rays and microwaves?
In this question, we are comparing X-rays and microwaves based on different properties. To find the correct answer, let's analyze each option:
a. X-rays have greater speed than microwaves.
The speed of electromagnetic waves, including X-rays and microwaves, is constant in a vacuum at about 3 x 10^8 meters per second. Thus, the speed of X-rays and microwaves is the same. This option is incorrect.
b. X-rays have greater amplitude than microwaves.
Amplitude refers to the maximum displacement of particles in a wave. It does not depend on the type of wave or its frequency. Comparing X-rays and microwaves, their amplitudes can vary depending on the source and intensity. So, this option is also incorrect.
c. X-rays have greater frequency than microwaves.
Frequency refers to the number of wave cycles per unit of time. X-rays have much higher frequencies than microwaves. Therefore, this option is correct.
d. X-rays have greater wavelength than microwaves.
Wavelength refers to the distance between two consecutive points in a wave. X-rays have much smaller wavelengths compared to microwaves. Hence, this option is incorrect.
Based on our analysis, the correct answer to question 1 is option c: X-rays have greater frequency than microwaves.
2. The wavelength of a longitudinal wave is the distance from
In this question, we are considering longitudinal waves and determining the meaning of wavelength for this type of wave. Let's break down the options:
a. Compression to rarefaction.
A longitudinal wave consists of compressions and rarefactions. The distance between a compression and a rarefaction is one complete wavelength. Therefore, this option is correct.
b. Compression to compression.
The distance between two compressions corresponds to one complete cycle or two wavelengths. So, this option is incorrect.
c. Crest to trough.
Crest and trough are terms used to describe transverse waves, not longitudinal waves. Therefore, this option is incorrect.
d. Crest to crest.
Again, this option is related to transverse waves, not longitudinal waves. Hence, it is incorrect.
The correct answer to question 2 is option a: compression to rarefaction.
3. What is one reason sound travels faster in liquid water than in air?
To answer this question, we need to consider the properties of sound and how it travels through different mediums. Let's analyze the options:
a. Air molecules are less elastic than liquid water molecules because air molecules have weaker attractions.
b. Air molecules are more elastic than liquid water molecules because air molecules have weaker attractions.
c. Air molecules are more elastic than liquid water molecules because air molecules have stronger attractions.
d. Air molecules are less elastic than liquid water molecules because air molecules have stronger attractions.
The speed of sound is influenced by the density and elasticity of the medium through which it travels. Elasticity refers to how easily a material can be compressed and then bounce back to its original state.
In the given options, option a states that air molecules are less elastic than liquid water molecules because air molecules have weaker attractions. This is incorrect because air molecules are indeed less dense and have weaker attractions compared to liquid water molecules, but they are more elastic. Air can be easily compressed and its molecules can quickly regain their original positions, increasing the speed of sound. So, option a is incorrect.
Option b also states that air molecules are more elastic than liquid water molecules because air molecules have weaker attractions. However, as mentioned earlier, air molecules are less dense and have weaker attractions compared to liquid water molecules. So, this option is incorrect.
Option c states that air molecules are more elastic than liquid water molecules because air molecules have stronger attractions. This is incorrect because air molecules have weaker rather than stronger attractions compared to liquid water molecules.
Option d states that air molecules are less elastic than liquid water molecules because air molecules have stronger attractions. This correctly reflects the comparison between air and liquid water. Air molecules are less elastic than liquid water molecules due to their weaker attractions. Liquid water molecules have stronger attractions, making them less compressible and therefore allowing sound waves to travel faster through water.
Therefore, the correct answer to question 3 is option d: Air molecules are less elastic than liquid water molecules because air molecules have stronger attractions.
1. c. X-rays have greater frequency than microwaves.
2. a. compression to rarefaction.
3. d. Air molecules are less elastic than liquid water molecules because air molecules have stronger attractions.