Sound Part Three: Ultrasound

Question 1

How can sound be used to make a picture?

Answer 1

Ultrasound

Question 2

What is ultrasound?

Answer 2

Sound with a frequency higher than 20,000 Hz. Above human hearing range

Question 3

How can ultrasound be made by electrical devices?

Answer 3

It can be used to create electrical oscillations (vibrations) with a range of frequencies (range of speeds for a wave) which can then be turned into mechanical vibrations to be able to be turned into sound waves over 20,000 Hz

Question 4

Ultrasound goes through something called partial reflection. What is that?

Answer 4

Ultrasound goes through partial reflection when they hit boundaries. When ultrasound passes from one medium to another some of the wave is reflected off the boundary and some is transmitted (passed into/through) and then refracts

Question 5

Because ultrasound can go through partial reflection, what does this mean we can use this fact to do?

Answer 5

You could point a pulse of ultrasound at a medium and wherever there are boundaries where one substance meets another, some of the wave will hit it and reflect off the boundary. When the time and distribution is recorded, you can use it to see how far something is from the detector.

Question 6

Ultrasound can be used for pre natal screening in the medical industry. How?

Answer 6

Ultrasound waves can pass through any medium, including the body. And you can send it through the body where it will bounce off the boundary where one substance meets another (fluid of womb + skin of foetus). Parts of the wave is reflected and they will be detected. The exact timing and distribution of the echos are recorded and then processed by a computer to generate an image of the foetus.

Question 7

Ultrasound is used in the industrial area to find flaws or cracks in some materials. How?

Answer 7

They can be used to find flaws in pipes or other material like wood or metal. They’ll send a wave to enter to material and the wave should partially bounce back where the end of said material is. If there is a flaw, it will bounce back early and they will be able to use the time is bounced back to calculate where the flaw is.

Question 8

What is echo location and how is it used?

Answer 8

You’ll use high frequency waves (including ultrasound) and it’ll be used by boats and submarines. They’ll send the waves down to find either the depth of the water or to find an object in DEEP water.

Question 9

If you’re given the speed of a sound wave and the time it took to reach somewhere and back how do you calculate the distance?

Answer 9

Speed = distance/time. You can divide any value by two. Either speed or time at the start or distance at the end

Question 10

If you are given the speed of a sound wave and the distance it travel to get somewhere and back, how would you find the time?

Answer 10

Instead of dividing by two you’ll times by two. You can’t times the speed, but you can either times the distance at the start or the time at the end.