Answer:
72.04 dB.
Step-by-step explanation:
The intensity level of 60dB corresponds to the sound intensity
given by the equation
![60dB = 10log((I)/(I_0) )](https://img.qammunity.org/2021/formulas/physics/middle-school/dugdi7opfjxlers5jntphv78euuncji49n.png)
where
![I_0 = 1*10^(-12)W/m^2](https://img.qammunity.org/2021/formulas/physics/middle-school/li425myut8pda23quswvc84d5ujd1tm0sc.png)
solving for
we get:
![6 = log((I)/(I_0) )](https://img.qammunity.org/2021/formulas/physics/middle-school/amf9jn62p6t08ptful7rssrm12x6daom72.png)
![10^6 =(I)/(1*10^(-12))](https://img.qammunity.org/2021/formulas/physics/middle-school/l9l0y7wam8re82ce7g68lua30bajf46iqg.png)
![\boxed{I = 1*10^(-6) W/m^2}](https://img.qammunity.org/2021/formulas/physics/middle-school/dkol09c6ntp3y53hxutdxv197s0flo6g5q.png)
Now, when 16 violins are playing the intensity
becomes
![{I = 16(1*10^(-6) W/m^2)](https://img.qammunity.org/2021/formulas/physics/middle-school/5d5l0n8dchg8pn832rwkdpq2uamgy8s326.png)
which on the decibel scale gives
![dB = 10log((16*10^(-6))/(1*10^(-12)) )](https://img.qammunity.org/2021/formulas/physics/middle-school/s7ch9cf5qdr3aodzlk0629vutvxlv7uws2.png)
.
Thus, playing 16 violins together gives the intensity level of 72 dB.