If f=140hz
speed=?
wavelength=?
without all information given, it would be difficult to answer but the formula is speed=frequency ×wavelength
Motorcycle helmets are padded to give the rider the protection they require in case of accidents. Any hit to the head is absorbed by the padding and the rider is saved from any kind of fatal injury. Whenever a motorcycle rider falls from his motorcycle, there is every possibility that the head will hit the ground first. If the padding was not there, then the rider would get the direct impact of hitting. As most of the pressure of the hit gets absorbed by the inner padding of the helmet, so the rider is saved from the fatal accident. It does not mean that the driver will not have minor injuries but by all chance his life would be saved.
Answer:
Explanation:
Caty , Use the relativity formula for length. ( they teach this in H.S. ? ) it's from my Modern Physics in college, A 300 level class
L = 

L = 3 
L = 0.9367496998 meters
L = 0.94 meters approx