Answer:

Explanation:
From the question we are told that:
Far point is 
Near point is 
Therefore
Focal Length

Generally the equation for the Lens is mathematically given by



Answer:
Explanation:
KE = ½Iω²
ΚΕ = ½(mL²/3)ω²
ΚΕ = ½(0.63(0.82²)/3)4.2²
ΚΕ = 1.24541928
KE = 1.2 J
Answer:
the force will decrease to 3/4 of its original value.
Explanation:
The initial electric force between the two charges is:

where
k is the Coulomb's constant
q is the magnitude of each charge
r is their separation
Later, half of one charge is transferred to the other charge; this means that one charge will have a charge of

while the other charge will be

So, the new force will be

So, the force will decrease to 3/4 of its original value.
<span>Assuming that the momenta of the two pieces are equal: when they have equal velocities, then
the masses of the two pieces are also equal.
Since there is no force from outside of the system, the center of mass moves on with the same velocity as before the equation. So the two pieces must fly at the side side of the mass center, i.e., they must always be at 90° to the side of the mass center. Otherwise it would not be the mass center, respectively the pieces would not have equal velocities.
This is only possible, when the angle of their velocity with the initial direction is 60°.
Because, cos (60°) = 1/2 = v/(2v).</span>