Все написано в скобках правильно
Answer:39.88 rad/s
Explanation:
Given
mass of cylinder m_1=18 kg
radius R=1.7 m
angular speed 
mass of 
dropped at r=0.3 m from center
let 
be the final angular velocity of cylinder
Conserving Angular momentum
Answer:
7 m .
Explanation:
For destructive interference
Path difference = odd multiple of λ /2
Wave length of sound from each of A and B.
= speed / frequency
λ = 334 / 172 = 2 m
λ/2 = 1 m
If I am 1 m away from B , the path difference will be
8 - 1 = 7 m which is odd multiple of 1 or λ /2
So path difference becomes odd multiple of λ /2.
This is the condition of destructive interference.
So one meter is the closest distance which I can remain at so that i can hear destructive interference.
Mechanical energy is the answer
Mechanical energy equals the sum of potential and kinetic energy. During the process, all PE converts into KE, assuming air resistance is neglected. So, the mechanical energy does not change and is equal to the initial potential energy.
ME
=mgh
=0.005 x 9.81 x 3
=0.147J
