Is this Wavelength answer correct?

  • Thread starter Thread starter onrytxn
  • Start date Start date
  • Tags Tags
    Wavelength
AI Thread Summary
The calculation for the wavelength of a 1.5 MHz sound wave in soft tissue uses the formula wavelength = velocity divided by frequency, resulting in 10.27 x 10^-4 m. This converts to 1.027 mm, which is longer than typical ultrasound wavelengths, usually less than 1 mm. The initial conversion to mm was incorrect, as 10.27 mm is not accurate for this frequency. The correct conversion emphasizes the importance of precise decimal placement in calculations. Understanding these conversions is crucial in ultrasound physics.
onrytxn
Messages
4
Reaction score
0
The question is: Calculate the wavelength of a 1.5 MHz sound wave that is being transmitted through soft tissue. (This is Ultrasound physics, if you are wondering.)
formula used: wavelength = velocity (1540 m/s) divided by 1.5 MHz

MHz changes to 1.5 x 10^6

so I have: 1540m/s / 1.5 x 10^6 1/s=10.27 x 10^-4m or 10.27mm


Is this correct? I'm worried about my conversion---I tend to mess up the most simple conversions.

Thx!

Kathy
 
Physics news on Phys.org
10.27 x 10-4m is correct, however it is not 10.27 mm (which is ~0.4 inch).

Ultrasound has short wavelengths, usually < 1 mm.

So 1 mm is 10-3 m.

10.27 x 10-4m = 1.027 x 10-3m = 1.027 mm, which is long for UT.
 
Thank you! Those darned old decimals get me every time!
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top