The correct option is D.
Sound proofing is usually achieved by using materials that absorbed or reduce sounds. Different materials are used in sounding proofing and these differ in their abilities to absorb or reduce sounds. The coefficient of absorption of a material refers to that material ability to absorb sound. The higher the percentage of a material absorption coefficient, the better the material's ability to absorb sound. Thus, in the question given above, the material with 62% absorption coefficient have the greatest ability of the three materials to absorb sound effectively. <span />
Answer:
Explanation:
Given
Mass of object (m)=6 kg
falling height(h)=10 m
mass of water(
)=600 gm
temperature of water =15
specific heat of water 
Let T be the Final Temperature of water
Here Object Potential Energy is converted into Heat energy which will be absorbed by water
Potential Energy(P.E.)
Heat supplied


T-16=0.234

This is not an efficient way of heating water as there is only
increase in temperature.
By definition, speed is the integral of acceleration with respect to time.
We have then:

As the acceleration is constant, then integrating we have:

Where,
vo: constant of integration that corresponds to the initial velocity
We observe then that the speed varies linearly when the acceleration is constant
.
Therefore, for constant acceleration, the velocity is changing.
Answer:
an object with a constant acceleration always have:
A. changing velocity
Answer:
The kinetic energy is 86.6 zepto joules.
Explanation:
Given that,
Number of orbit n =5
We know that,
Bohr's radius for hydrogen atom is

Now, put the value of n in the formula of radius


We need to calculate the kinetic energy
Using formula of kinetic energy

Put the value into the formula


We know that,

The kinetic energy is


Hence, The kinetic energy is 86.6 zepto joules.
Due to the shape of the lens , parallel rays will be deviated