The electric field in a certain region of Earth's atmosphere is directed vertically down. At an altitude of 241 m the field has magnitude 46.8 N/C; at an altitude of 93.9 m, the magnitude is 114 N/C. Find the net amount of charge contained in a cube 147.1 m on edge, with horizontal faces at altitudes of 93.9 m and 241 m.

Explanation:

We shall apply Gauss's Law to find the solution .

flux entering the cube = E X A

= 46.8 X 147.1 X 147.1 Weber

flux going out of cube

= 114 x  147.1 X 147.1  Weber

Net flux going out

= ( 114 x  147.1 X 147.1  - 46.8 X 147.1 X 147.1 )

= 1454101.15 weber .

according to Gauss's law

q / ε₀ = 1.4541 x 10⁶ , q is required charge inside the cube.

q = 8.85 x 10⁻¹² x 1.4541 x 10⁶

= 12.868 x 10⁻⁶ C

= 12.868 μC.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

not too sure thinking all accelerations are pointed down