What determines the acoustic impedance of a material and why is it useful in understanding ultrasound imaging?
Acoustic impedance is the density of a material multiplied by the speed of sound in the material.
Knowing these two values allows use to calculate how much of the sound energy is reflected at an interface between two materials, or two different types of tissue in the body. The greater the difference, the more reflection. This is the reason for the use of coupling gel between the scanner probe and the skin, removing trapped air, to reduce reflection of ultrasound at the skin, by reducing the acoustic impedance difference.
DA
Related Physics A Level answers
All answers ▸If a ball is launched at ground level at a velocity v and angle θ, find an expression for it's height at horizontal distance x.
A cannon ball is shot at an angle of 60 degrees from a cliff of height 50m, if it's inital speed is 20ms^-1 what horizontal distance does it travel before hitting the ground.
Two cars start at point A. Car 1 moves in a direction at 5 m/s. After 10 seconds car 2 accelerates in the same direction as car 1 at 2m/s^2. At what time after car 1 starts moving and distance from A does car 2 pass car 1?
I dont really understand the Rutherford experiment