Loudspeakers can produce intense sounds with surprisingly small energy input in spite of their low efficiencies. Calculate the power input needed (in W) to produce a 89.6 dB sound intensity level for a 13.0 cm diameter speaker that has an efficiency of 2.06%. (This value is the sound intensity level right at the speaker.)

Explanation:

Given that:

Efficiency = 2.06 % = 0.0206

The  intensity level of sound is given by the formula:

Taking their exponential; we have :

Replacing our values; we have:

Power Output;

The power output that is required to produce a 89.6 dB sound intensity level for a 13.0 cm diameter speaker that has an efficiency of 2.06% is;

Therefore, The power output that is required to produce a 89.6 dB sound intensity level for a 13.0 cm diameter speaker that has an efficiency of 2.06% is

the bal will not change its velocity.