LOL xaM

Question 1

What is the range of Hooke’s law validity?

Answer 1

Region until the elasticity limit (elastic)

Question 2

What does an isotropic material mean?

Answer 2

A material with uniform properties throughout in all directions.

Question 3

What is the difference between a strain and mechanical stress?

Answer 3

Mechanical stress is a force per unit area within materials that arises from
externally applied forces, while a strain is the measure of the deformation of
the material.

Question 4

What are the two basic components of a bone?

Answer 4

Flexible fibers of collagen and brittle chains of the calcium-rich mineral
hydroxyapatite.

Question 5

What are the factors affecting the elasticity of bone?

Answer 5

The stress duration, the fluid content of the specimen, bone temperature, the
vascular pattern of the bone.

Question 6

If the initial length of a spring is doubled,

Answer 6

the spring’s constant become twice smaller.

Question 7

Which of these statements for simple harmonic oscillations is true?

Answer 7

The instant acceleration of an oscillating object is the largest when it is the
furthest from equilibrium.

Question 8

Which two of these oscillation types can be used to describe a beating heart?

Answer 8

Forced, because the heart receives continuous input from the nervous system.
· Damped, because in natural conditions there are always energy losses due to friction.

Question 9

Angular frequency is

Answer 9

the frequency of a steadily recurring phenomenon expressed in radians per
second;

Question 10

A model based on a harmonic oscillator describing human walking and balance

Answer 10

can be represented with the sinusoidal trajectory of the center of mass of a
subject.

Question 11

During one full oscillation the phase changes:

Answer 11

by 2π radians (360 degrees)

Question 12

Which wave types can be used to characterize a sound wave propagating in
air? Select two options.

Answer 12

Mechanical wave

Longitudinal wave

Question 13

Sound intensity

Answer 13

○ Is proportional to the sound power
○ Is proportional to the sound energy
○ Unit is watts per square meter

Question 14

What is the quantity defined as the time for one sound wave?

Answer 14

Period

Question 15

Which sound has a higher pitch?

Answer 15

Craziest and highest one

Question 16

The sound intensity I is measured as sound power P per unit area A in Watts per
square meter (W/m2)?

Answer 16

True

Question 17

Every 10dB sound intensity doubles?

Answer 17

False

Question 18

When two (or more) waves travel simultaneously in the same medium, the total
disturbance in the medium is at each point the vectorial sum of the individual
disturbances produced by each wave

Answer 18

True

Question 19

It is possible to focus the light, but impossible to focus the sound

Answer 19

False

Question 20

The distance between the nearest equal points on the sound wave is called
amplitude.

Answer 20

False

Question 21

The response of the ear to the sound intensity is closer to being linear than
logarithmic

Answer 21

False

Question 22

Acoustic impedance depends on the density of the material and the speed of
sound in a given material.

Answer 22

True

Question 23

The sound wave in the air is a mechanical transverse wave.

Answer 23

False

Question 24

The nerves in the ear are not the only ones that respond to the sound pressure
wave, as most of the skin contains nerves that are more sensitive to pressure
variations

Answer 24

False

Question 25

When the ultrasonic wave passes an interface of two mediums that have similar acoustic impedance, almost no reflection of this wave occurs.

Answer 25

True

Question 26

If the sound source is moving towards the observer, the amplitude of the sound will seem to be larger, compared to an unmoving source at the same distance away.

Answer 26

False

Question 27

Medical ultrasound uses the Doppler effect to measure the velocity of the blood flow. This can be used to detect blood clots, for example, in vein thrombosis diagnostics.

Answer 27

True

Question 28

The ultrasound wavelength increases when the frequency is decreased, but the light wavelength increases when the frequency is increased.

Answer 28

False

Question 29

This relationship between frequency (f), wavelength (λ), and speed (v) is true for wave motion.

Answer 29

True

Question 30

Piezoelectric crystals are used to generate ultrasound. The same crystals are also used to detect echoes in ultrasonography.

Answer 30

True

Question 31

Acoustic impedance is a property of a tissue, which describes resistance to the propagation of an ultrasound wave through the tissue. Acoustic impedance value dependent on the tissue thickness.

Answer 31

True