Answer: 39.8 μC
Explanation:
The magnitude of the electric field generated by a capacitor is given by:

d is the distance between the plates.
For a capacitor, charge Q = CV where C is the capacitance and V is the voltage.

where A is the area of the plate and ε₀ is the absolute permittivity.
substituting, we get

It is given that the magnitude of the electric field that can exist in the capacitor before air breaks down is, E = 3 × 10⁶ N/C.
radius of the plates of the capacitor, r = 69 cm = 0.69 m
Area of the plates, A = πr² = 1.5 m²
Thus, the maximum charge that can be placed on disks without a spark is:
Q = E×ε₀×A
⇒ Q = 3 × 10⁶ N/C × 8.85 × 10⁻¹² F/m × 1.5 m² = 39.8 × 10⁻⁶ C = 39.8 μC.
Answer:
0 m/s
Explanation:
Relative speed is defined as the speed of an object with respect with another object.
In other words, it is the speed of an object as viewed from the frame of reference of another object.
When two objects are moving in the same direction, their relative velocity is given as:

where
velocity of first object
velocity of second object
In the case of the two cars,
22 m/s
Therefore:

Their relative velocity is 0 m/s.
Answer:
The charge of ions must be balance
Explanation:
Ionic compound: It is that compound which consist of positive and negative ions and ions held together by electrostatic force.Electric force is that force which act between two charges.
The compound is neutral because negative ions is equal to positive ions in the ionic compound.
The charge of ions must be balance.It is necessary condition for writing a formula for an ionic compound.
Hence,the charge of ions must be balance is that condition which must be met when writing a formula for an ionic compound.
In empty space, there's nothing to exert force on the ball after it leaves
her hand. It sails away in a straight line, at constant speed of 13 m/s.
If it doesn't sail too close to a planet, a star, an asteroid, or a moon, it
may travel 6 billion light years and still be moving at 13 m/s.