The current is defined as the amount of charge Q that passes through a given point of a wire in a time

:

Since I=500 A and the time interval is

the charge is

One electron has a charge of

, therefore the number of electrons that pass a point in the wire during 4 minutes is

electrons
Metallic bonds! Hope this helps!! :))
Answer:
(a) -472.305 J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305 J=-472.305 J
(b)
From fundamental kinematic equation

Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
but a=\mu g hence

Answer:
They are gaining energy, can move and slide past each other.
Explanation:
Because as ice melts, the molocules gain energy/heat which warm them up and are able to slide/move apart from each other.
Answer:
it decreases in size
Explanation:
The reason why this happens is simply just condensation. unlike when water is boiling, that is evaporating