Answer:
μ= 0.3
Explanation:
Given that
F= 33 N
m = 11 kg
Given that crate is moving with constant velocity is means that acceleration of the crate is zero.If acceleration of the system is zero then the total force on the system will be balance.
Therefore
F= Friction force
F= μ m g
μ=Coefficient of friction
33 = μ x 10 x 11 ( take g= 10 m/s²)
3 = 10 μ
μ= 0.3
Therefore coefficient of friction will be 0.3 .
Answer:
n = 1.42
Explanation:
The refractive index for a medium is given by the ratio of the speed of light in vacuum to the speed of light in a medium.

So, the refractive index of the medium is 1.42.
Mechanical
waves are oscillation of matter, they are important because they all
transfer energy from one place to another. There are 2 types of
mechanical waves. A transverse wave where the particles vibrate
perpendicular to the direction of energy travel and a longitudinal
wave where particle vibrations are parallel to the direction of the
energy transfer.
I
hope it helps, Regards.
'A' is correct. B, C, and D are false statements.
Answer:
The charge on the dust particle is 
Explanation:
From the question we are told that
The length is 
The width is 
The charge is 
The mass suspended in mid-air is 
Generally the electric field on the carpet is mathematically represented as

Where
is the permittivity of free space with value 
substituting values


Generally the electric force keeping the dust particle on the air equal to the force of gravity acting on the particles

=> 
=> 
=> 
=> 