<span>C.
Sample C would be best, because the percentage of the energy
in an
incident wave that remains in a reflected wave from this material
is the
smallest.
The coefficient of absorption is the percentage of incident sound
that's absorbed. So the highest coefficient of absorption results in
the smallest </span><span>percentage of the energy in an
incident wave that remains.
That's what you want. </span>
Answer:

Explanation:
The total charge is distributed over the two objects:

The plate and the rod must have
. So the charge transferred from the plate to the rod is:

Number of electrons:

Answer:
4.2 J
Explanation:
Specific heat capacity: This is defined as the amount of a heat required to rise a unit mass of a substance through a temperature of 1 K
From specific heat capacity,
Q = cmΔt.............................. Equation 1
Where Q = amount of energy absorbed or lost, c = specific heat capacity of water, m = mass of water, Δt = Temperature rise.
Given: m = 1 g = 0.001 kg, Δt = 1 °C
Constant : c = 4200 J/kg.°C
Substitute into equation 1
Q = 0.001×4200(1)
Q = 4.2 J.
Hence the energy absorbed or lost = 4.2 J
When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
Answer:
(i)
, (ii)
, (iii) 
Explanation:
(i)
and
represent the points where particle has a velocity of zero and spring reach maximum deformation, Given the absence of non-conservative force and by the Principle of Energy Conservation, the position where particle is at maximum speed is average of both extreme positions:

(ii) Maximum accelerations is reached at
and
.

(iii) Greatest net forces exerted on the particle are reached at
and
.
