Explanation :
Absorption coefficient of a material determines how much sound is absorbed by the material.
To build a soundproof room, Heavy curtains and carpet can be used. They reduce reverberation.
Reverberation means an echoing sound which persists for some time. For example, when we bang on a huge piece of metal, we hear the reverberation even after we stop banging.
Hence, option (A) and (D) are correct.
Answer:
0 N.
Explanation:
Force: This can be defined as the product of mass and the acceleration of the body. The S.I unit of force is Newton (N).
The expression of net force when both force act in the different direction is given as
F' = W-F ........................ Equation 1
Where F' = Net force on the bag, W = gravitational force on the bag, F = Force acting upward on the bag
Given: W = 18 N, F = 18 N.
Substitute into equation 1
F' = 18-18
F' = 0 N.
Hence the net force = 0 N.
In the experiment of free fall bob released a bag of mass 1 lb
so here we can say that initial speed of the bag is Zero
time taken by the bag to free fall is given as
t = 1.5 s
also the acceleration of free fall is given as
a = 9.8 m/s^2
now we will use kinematics equation here for finding the distance of free fall




so the bag will fall down by total distance of 11.025 m from its initial released position.
Explanation:
(1). Formula to calculate the potential difference is as follows.
= 
= 
= 
= 
= 38.7 volts
Therefore, magnitude of the potential difference between the two spheres is 38.7 volts.
(2). Now, formula to calculate the energy stored in the capacitor is as follows.
E = 
= 
= 
Thus, the electric-field energy stored in the capacitor is
.