The expression of the electric flux is

Here,
Q = Total charge enclosed in the closed surface
= Permittivity due to free space
Rearranging to find the charge,

Replacing with our values we have finally



The charge enclosed by the box is 0.1684nC
The sign of the charge can be decided by using the direction of the flux. The charge enclosed by the cube can be calculated by using the electric flux and the permitivity of free space.
Answer:
The value is 
Explanation:
From the question we are told that
The mass of each sphere is 
The length of the string is
The angle of with the vertical is 
The acceleration due to gravity is 
Generally the force acting between the forces is mathematically represented as

=> 
Generally from Pythagoras theorem the radius of the circular curve created by the force is

=> 
=>
=> 
=> 
=> 
Explanation:
It is given that,
Mass of the tackler, m₁ = 120 kg
Velocity of tackler, u₁ = 3 m/s
Mass, m₂ = 91 kg
Velocity, u₂ = -7.5 m/s
We need to find the mutual velocity immediately the collision. It is the case of inelastic collision such that,


v = -1.5 m/s
Hence, their mutual velocity after the collision is 1.5 m/s and it is moving in the same direction as the halfback was moving initially. Hence, this is the required solution.
According to the right-hand thumb rule, the forefinger gives the velocity of charge, the thumb gives the magnetic force and the center finger gives the direction of magnetic field.
then, as shown in the picture, the <span>direction of the magnetic force on the charge is in the right direction.</span>