A 1/2kg book is shoved across the table with an initial velocity of 2m/s. If it slides for a meter before coming to rest. a) what was its acceleration? Technically, this acceleration is negative, since the book is slowing downing.
b) What was the frictional force?

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

mistakes are ok

unbalanced force

explanation:

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.