A capacitor is made from two hollow, coaxial, iron cylinders, one inside the other. The inner cylinder is negatively charged and the outer is positively charged; the magnitude of the charge on each is 15.5 pC. The inner cylinder has a radius of 0.600 mm, the outer one has a radius of 5.20 mm, and the length of each cylinder is 25.0 cm.

(a) What is the capacitance?
(b) What applied potential difference is necessary to produce these charges on the cylinders?

(a). The capacitance is

(b). The potential difference is necessary to produce these charges on the cylinders are 2.41 V.

Explanation:

Given that,

Charge = 15.5 pC

Inner Radius = 0.600 mm

Outer radius = 5.20 mm

Length = 25.0 cm

(a). We need to calculate the capacitance

Using formula of capacitor

Put the value into the formula

The capacitance is

(b). We need to calculate the potential difference is necessary to produce these charges on the cylinders

Using formula of charge

Put the value into the formula

Hence, (a). The capacitance is

(b). The potential difference is necessary to produce these charges on the cylinders are 2.41 V.

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.