Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
Answer:
Explanation:
All substances have characteristic physical and chemical properties. Physical properties are those that can be observed with the senses without changing the identity of the substance. Chemical properties describe how a substance can be changed into a new substance. Physical and chemical properties, such as color, density, boiling point, solubility, conductivity, and flammability, A. are always different between substances. B. depend on the amount of the substance. C. do not depend on the amount of the substance. D. have the same values for all substances.
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Answer:
it's B. circuit a and b are series circuit while c is parallel
The equivalent resistance of n resistors in series is given by:
In our circuit, we have three resistors of
each, therefore the equivalent resistance of the circuit is
