Answer :
Essay on Sound instruments/sound boxes:
Musical instruments also some times called <em>"sound box"</em>, because the box modifies the sound of an instrument. It also helps in transfer of sound to the surrounding air.
The box is the open chamber in the body of musical instrument
The sound box responds more strongly to vibrations at certain frequencies created by playing instrument. This phenomena is known as resonance.
The resonance impacts on the tone quality.
For example <em>xylophone</em>, which is a musical instrument with wooden bars. These wooden bars are arranged similar to the piano. under each bar of the xylophone there is a resonator tube, which amplifies the sound.
Their cognitive skills and their ability to learn
Answer:
Impedance, Z = 107 ohms
Explanation:
It is given that,
Resistance, R = 100 ohms
Inductance, 
Capacitance, 
Frequency, f = 60 Hz
Voltage, V = 120 V
The impedance of the circuit is given by :
...........(1)
Where
is the capacitive reactance, 

is the inductive reactance, 

So, equation (1) becomes :

Z = 106.26 ohms
or
Z = 107 ohms
So, the impedance of the circuit is 107 ohms. Hence, this is the required solution.
The exact location of the 'subtropical-jet stream' is located at the North phase of 30 Degrees and the reason behind this is due to the variation of air which lies on the region of mid-altitude and warmer equatorial air. the correct answer would be Cool and Warm air masses meeting near the equator.