Easy !
Take any musical instrument with strings ... a violin, a guitar, etc.
The length of the vibrating part of the strings doesn't change ...
it's the distance from the 'bridge' to the 'nut'.
Pluck any string. Then, slightly twist the tuning peg for that string,
and pluck the string again.
Twisting the peg only changed the string's tension; the length
couldn't change.
-- If you twisted the peg in the direction that made the string slightly
tighter, then your second pluck had a higher pitch than your first one.
-- If you twisted the peg in the direction that made the string slightly
looser, then your second pluck had a lower pitch than the first one.
Answer:
Same frequency, shorter wavelength
Explanation:
The speed of a wave is given by


where,
f = Frequency
= Wavelength
It can be seen that the wavelength is directly proportional to the velocity.
Here the frequency of the sound does not change.
But the velocity of the sound in air is slower.
Hence, the frequency remains same and the wavelength shortens.
<u><em>In accordance with the International Regulation for the prevention of collisions at sea</em></u><u>:
</u>
<u>1.- A sailing boat has a passing preference over a motorized boat, </u><u>except when the motor boat is limited by its draft</u><u>.
</u>
<u>2.- The sailboat must maintain its course and speed.
</u>
<u>3.- </u><em><u>If it is evident that the PWC does not respond</u></em><u>, the sailboat must sound the warning signal, and change its course to starboard.
</u>
<u>4.- </u><u><em>All actions must be taken as soon as possible</em></u><u>.
</u>
<u>5.- If a sailboat is using its engine, the situation changes, and in that case, both ships must alter to starboard.</u>
Answer:
iron and red blood is require