Unit: Mechanics
Year: 1990 Question#: 15
Question: A copper coin resting on a piece of cardboard is placed on a beaker as shown in the diagram at the right. When the cardboard is rapidly removed, the coin drops into the beaker. The two properties of the coin which best explain its fall are its weight and its
(1 ) temperature
(2 ) electrical resistance
(3 ) volume
(4 ) inertia
What is this question really asking?
Explanation by: Michelle H
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Answer 1
temperature
INCORRECT
This answer is incorrect because temperature is the property of a material that tells how warm or cold it is with respect to some standard. Temperature has nothing to do with why the penny falls. return to top
Answer 2
electrical resistance
INCORRECT
This answer is incorrect because electrical resistance refers to the resistance of a material to the flow of an electric current through it. Electrical resistance has nothing to do with why the penny will fall when the cardboard is removed. return to top
Answer 3
volume
INCORRECT
This answer is incorrect because volume is a measure of space. The volume of the penny refers to how much space it takes up, it does not determine whether or not the penny will fall when the cardboard is removed. return to top
Answer 4
inertia
CORRECT
This answer is correct because Newton's first law states that: Every object in its state of rest will remain at rest unless acted upon by an unbalanced force, and any object in motion continues in straight line motion unless acted upon by an unbalanced force. The cardboard that the penny was sitting on was removed, exerting a force on it and setting it into motion. return to top
What's this question really asking?
This is another question that comes down to knowing your definitions. If you know what each possible answer meant then this question was relatively easy to answer. return to top
