Brochure Answers Question Match the quote with the physicist  1.   “A person who never made a mistake never tried anything new.”   2.   “If I have seen further it is by standing on the shoulders of giants.”   3.   "My goal is simple. It is complete understanding of the universe, why it is as it is and why it exists at all."   4.   “It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.”   A.  Isaac Newton B.   Albert Einstein C.  Richard Feynman D.  Steven Hawking Answer 1B   2A   3D   4C   Question The ultimate fate of the Sun is represented by the Helix Nebula, 650 light years away. When will the Sun end its life as a star? Answer C. A few billion years

Question

Two beakers containing water are balanced on an equal arm balance.  Will the balance remain balanced if you dip your fingers into the water of one of the beakers?  If not, which side of the balance drops?

Answer

The left pan drops when the person dips her fingers into the water.

Explanation

When an object is placed in water, the water will exert a buoyant force upon that object in the upward direction.  For example, a boat floats because the upward buoyant force by the water counters the boat’s weight that is directed downward.  Hence, when the person dips her fingers into the water in the diagram, the water exerts an upward directed buoyant force upon her hand. 

Newton’s Third Law states that whenever one object exerts a force upon a second object, then the second object exerts and equal and opposite force upon the first.  Since the water exerts an upward force on the hand, the hand must exert a downward force on the water.  Hence, since the person exerts a downward force on the water in the left beaker, the left pan will drop.