The density of mobile electrons in copper metal is 8.4 1028 m-3. Suppose that i = 4.6 1018 electrons/s are drifting through a copper wire. (This is a typical value for a simple circuit.) The diameter of the wire is 1.2 mm. In this case, about how many minutes would it take for a single electron in the electron sea to drift from one end to the other end of a wire 31 cm long?

The time is 106.7 minute.

Explanation:

Given that,

Density

Current

Diameter of wire = 1.2 mm

Length = 31 cm

We need to calculate the drift velocity

Using formula of drift velocity

Put the value into the formula

We need to calculate the time

Using formula for time

Where, l = length

= drift velocity

Put the value into the formula

Hence, The time is 106.7 minute.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.