I'm not sure about the magnitude, but the direction of the normal force is upward.
There will not be enough momentum from the first hill to cross another hill if he same or larger size because of the way potential energy and kinetic energy works it will not be able go as high as it could go on he fist hill.
No, you can't aim where you see the fish, because refraction will change the position of the fish and make it appear in a different position from where it actually is.
Hope this helps!
Answer: The correct answer is "trumpet".
Explanation:
Resonance occurs when the applied frequency on the object is equal to the natural frequency of the object.
Wind instruments use resonance in the air column to amplify the sound. It makes the sound louder. Sound is produced by using lips or vibrating reeds or buzzing sound into the mouthpiece.
Therefore, resonance in air column is used in trumpet musical instruments.