Answer:
<em> The intensity would be 0.01432 W/</em>
<em></em>
Explanation:
The sound intensity is the power that is transmitted by a sound wave per unit area.
Given that
Power output P of the 75-piece orchestra = 72.0 W
The listener's distance r = 20.0 m
The intensity of sound waves (I) can be obtained with the expression below;
I = P/A .............. 1
where P is the power
A is the area, in this case, at the distance r the sound is radiated through a sphere.
A = area of a sphere = 4π
putting it into equation 1, the intensity would be;
I = P/ 4π
Substituting our values we have;
I = 72.0 W / 4 π

I = 0.01432 W/
Therefore the intensity would be 0.01432 W/
Im not sure if this is physics or mathematics. but if 300 msec then per minute this will equal to 300 X 60 sec =18000 m per minute
Answer:7.92 N
Explanation:
Given
mass of book 
coefficient of static friction 
coefficient of kinetic friction 
To move the book, one need to overcome the static friction
Static friction 



After overcoming the Static friction , Force needed to move the block is



Work Done = Force * Distance
This means the least work is exerted by the most distance, so the longer ones are less likely to break.
The shortest one will be the one that breaks easiest.