Answer:
a) I = 3.63 W / m²
, b) I = 0.750 W / m²
Explanation:
The intensity of a sound wave is given by the relation
I = P / A = ½ ρ v (2π f 
)²
I = (½ ρ v 4π² s_{max}²) f²
a) with the initial condition let's call the intensity Io
cte = (½ ρ v 4π² s_{max}²)
I₀ = cte s² f₀²
I₀ = cte 10 6
If frequency is increase f = 2.20 10³ Hz
I = constant (2.20 10³) 2
I = cte 4.84 10⁶
let's find the relationship of the two quantities
I / Io = 4.84
I = 4.84 Io
I = 4.84 0.750
I = 3.63 W / m²
b) in this case the frequency is reduced to f = 0.250 10³ Hz and the displacement s = 4 s or
I = cte (f s)²
I = constant (0.250 10³ 4)²
I = cte 1 10⁶
the relationship
I / Io = 1
I = Io
I = 0.750 W / m²
Answer: When rubbing a balloon with a wool cloth, it puts negative charges on the balloon. Negative charges attract to positive charges. If a balloon is not rubbed with the wool cloth, it has an equal amount of negative to positive charges, so it will attract to a rubbed balloon.
You need to know the speed and direction of object
<span>Nuclear energy can be used to power all of
the above choices. Nuclear power plants produce radioactive waste that must be
stored properly. It is very impossible for a nuclear power plant to have no
waste at all since lots of chemicals are used to create the process as it gives
energy to other machines, weapons such as bombs and powering submarines. Radioactive waste can not be released into
local water supplies since the wastes are very radioactive and may cause
mutation to the fishes and bioaccumulation which will affect humans as well. It
will also cause air pollution if the chemicals are not stored properly.</span>
