Human ears can hear sound waves that vibrate in the range from about 20 times a second (a deep rumbling noise) to about 20,000 times a second (a high-pitched whistling). (Children can generally hear higher-pitched sounds than their parents, because our ability to hear high frequencies gets worse as we get older.) Speaking more scientifically, we could say that the sounds we can perceive have a frequency ranging from 20–20,000 hertz (Hz). A hertz is a measurement of how often something vibrates and 1 Hz is equal to one vibration each second. The human voice makes sounds ranging from a few hundred hertz to a few thousand hertz.Suppose you could somehow hit a drum-skin so often that it vibrated more than 20,000 times per second. You might be able to see the skin vibrating (just), but you certainly couldn't hear it. No matter how hard you hit the drum, you wouldn't hear a sound. The drum would still be transmitting sound waves, but your ears wouldn't be able to recognize them. Bats, dogs, dolphins, and moths might well hear them, however. Sounds this like, with frequencies beyond the range of human hearing, are examples of ultrasound.Infrasonics, vibrational or stress waves in elastic media, having a frequency below those of sound waves that can be detected by the human ear—i.e., below 20 hertz. The range of frequencies extends down to geologic vibrations that complete one cycle in 100 seconds or longer.
Answer:
Explanation:
To focus object at .7m , the image distance can be measured as follows
object distance u = .7m
focal length f = .05 m
image distance v = ?
from lens formula
![\frac{1}{v} -\frac{1}{u} = \frac{1}{f}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bv%7D%20-%5Cfrac%7B1%7D%7Bu%7D%20%3D%20%5Cfrac%7B1%7D%7Bf%7D)
![\frac{1}{v} +\frac{1}{.7} = \frac{1}{.05}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bv%7D%20%2B%5Cfrac%7B1%7D%7B.7%7D%20%3D%20%5Cfrac%7B1%7D%7B.05%7D)
![\frac{1}{v} =\frac{1}{.05} -\frac{1}{.7}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bv%7D%20%3D%5Cfrac%7B1%7D%7B.05%7D%20-%5Cfrac%7B1%7D%7B.7%7D)
v = .054 m
= 54 mm
when the object is at infinity , image is formed at focus ie at distance of
50 mm .
So lens position from sensor where image is formed , varies from 54 mm to 50 mm .
Answer:
C. means that the natural variation of the process must be small enough to produce products that meet the standard.
Explanation:
Process capability is the statistical measure of the inherent process variability of a given characteristics. we ca use a process capability study to assess the capability of a process to meet specification.
C. means that the natural variation of the process must be small enough to produce products that meet the standard.
Answer:
4.167
Explanation:
ittravels 4.167metres per second
Answer:
i think it's 50 N
i might be wrong though not sure