The closer the particles, the more will be the propogation of sound waves. Room contains air molecules which are far away from each other. So it takes much time for one molecule of air to disturb the other one. But in case of solids, as particles are much closer(compared to fluids), disturbance generated by one molecule is quickly transmitted to the next molecule
Answer:
0.5 kg
Explanation:
The momentum of an object is defined as
p = mv
where
m is the mass
v is the velocity
In this problem we have,
v = 15 m/s is the velocity of the stone
p = 7.5 kg m/s is the momentum
Solving for m, we can find the mass of the stone:

Answer:0.114 C
Explanation:
Given
Total 4.7 C is distributed in two spheres
Let
and
be the charges such that

and Force between charge particles is given by



put the value of 




thus 