Answer:
Part a)

Part b)

Explanation:
Part a)
Electric field due to large sheet is given as







now the electric field is given as


Part b)
Now since the electric field is required at same distance on other side
so the field will remain same on other side of the plate

To solve this exercise it is necessary to apply the kinematic equations of angular motion.
By definition we know that the displacement when there is constant angular velocity is

From our given data we know that,



Moreover we know that

Therefore for time t=8.1s we have,



That number in revolution is:


Here, we see that there are 15 complete revolutions
And 0.108 revolutions i not complete, so the tunable rotation is

Therefore the angle of the speck at a time 8.1s is 
Answer:
pu = 1260.9kg/m^3
the density of the unknown liquid is 1260.9kg/m^3
Explanation:
The density of a liquid is inversely proportional to the volume (height) of object submerged in it.
High density liquid possess higher buoyant force preventing objects from submerging.
p ∝ 1/V ∝ 1/h
since V = Ah
pu/pw = hw/hu
pu = pwhw/hu
Where;
p = density
h = height submerged
pu and pw is the density of unknown liquid and water respectively
hu and hw is the height of object submerged in unknown liquid and water respectively
pw = 1000kg/m^3
hu = 4.6cm = 0.046m
hw = 5.8cm = 0.058m
Substituting the given values;
pu = 1000×0.058/0.046
pu = 1260.9kg/m^3
the density of the unknown liquid is 1260.9kg/m^3
Answer:D
Explanation:
Given
mass of object 
Distance traveled 
velocity acquired 
conserving Energy at the moment when object start falling and when it gains 12 m/s velocity
Initial Energy
Final Energy

where
is friction work if any


Since Friction is Present therefore it is a case of Open system and net external Force is zero
An open system is a system where exchange of energy and mass is allowed and Friction is acting on the object shows that system is Open .
Answer:
Collision force will be same in both the cases.
Explanation:
A perfectly inelastic collision is said to take place when a system loses the amount of its Kinetic Energy at its maximum. In a perfectly inelastic collision, the colliding particles stick to each other. In such a collision, kinetic energy is lost by combining the two bodies with each other.
In situation 1:
Speed of Car A, 
Speed of Car B, 
Relative speed of car A and car B, 
Now, in the situation 2:
Speed of car A, 
Speed of car B, 
Relative speed of car A and car B, 
Therefore, Car A and Car B both have the same relative speed, v = 10 m/s