football hemets have pads that are filled with air and thick foam so when they are hit the foam asorbs the hit and the air keeps the hard outer shell of the helmet from hiting the players head
Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
Photovoltaic cells are the most efficient means of converting solar energy to electricity. Option b is correct.
<h3>What is a cell?</h3>
A cell is a voltage and current-producing device that consists of a single anode and cathode separated by an electrolyte.
One or more cells can make up a battery. One cell, for example, is one AA battery.
Light intensity on a solar cell is often measured in "suns," with one sun roughly equivalent to 1 kW/m².
Concentrated sunlight improves the ratio of current generated while the device is lighted vs when it is dark, hence enhancing output voltage and efficiency.
Photovoltaic cells are the most efficient means of converting solar energy to electricity.
Hence, option b is correct.
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Diagram D. shows the sound waves generated by a siren
that is moving with constant speed to the left.
A sound wave is the sample of disturbance caused by the movement of strength journeying thru a medium because it propagates far away from the supply of the sound. Sound waves are created by using object vibrations and bring strain waves, for example, a ringing cellular phone.
Sound waves fall into three classes: longitudinal waves, mechanical waves, and strain waves. keep studying to find out what qualifies them as such. Longitudinal Sound Waves A longitudinal wave is a wave wherein the movement of the medium's debris is parallel to the course of the energy transport. Sound propagates via air or different mediums as a longitudinal wave, in which the mechanical vibration constituting the wave occurs along the direction of propagation of the wave.
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