You haven't said how much power the stereo uses. It matters !
Whatever that number is, the maximum hours per month is
(3460) divided by (the # of watts the stereo uses when it's playing) .
Answer:
Explanation:
Given
there is fix Quantity of gas i.e. mass of gas is constant
From ideal gas Equation
PV=nRT
(a) volume always increases is not true as Pressure can also be increased .
(b)If Pressure is constant along with mass then as Temperature increases, Volume also increases.
(c)true , Product of Pressure and volume depends upon temperature thus it also increases with temperature.
(d)Density of gas may or may not increases
As density is 
volume may increase or decrease as temperature increase .
(e)false
as it clearly stated that quantity of fixed therefore there is no change in gas
Answer:
Gravitational Potential Energy
Explanation:
a ball is held rest at the top of hill
gravitational potential energy will store due to its height
it. and body will start move downward and its potential energy will convert into kinetic energy due to motion of body
at the ground level it will stop and potential energy will became zero and kinetic energy get convert into internal energy due to collisions
I believe that it is electric field