To know the density you also need to know the volume of the rock.
Answer:
answer in expl.
Explanation:
example of false solution.- Earth is not square
true eg. - we live in earth
"A contactor is a electrically controlled switch which uses an electromagnetic coil to pull in the contacts.”
"A motor starter is a contactor, plus an overload relay that will drop out the coil voltage if the motor overloads. If there is not overload relay, it is not a starter any longer, it's back to being just a contactor."