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mitchell (jm56986) – HW #9 – montgomery – (24131) 1
This print-out should have 20 questions.
Multiple-choice questions may continue on
the next column or page – find all choices
before answering.
001 10.0 points
Why do ice cubes float?
1. Ice cubes are less dense than water. cor-
rect
2. Ice cubes are lighter than water.
3. Ice cubes are in a solid state.
Explanation:
Ice cubes are less dense than water. If ice
were more dense than water, it would sink,
and the bottom of ponds and oceans could be
covered by ice during the winter.
002 10.0 points
Which situation is likely to hurt you more?
1. Your bare foot was stepped on by a 130-lb
woman wearing high heels. correct
2. Your bare foot was stepped on by a 270-lb
man wearing flat-soled loafer.
3. Either
4. Unable to determine
Explanation:
P =
F
A
Pressure increases for a given force when the
area decreases.
003 10.0 points
What is the pressure if a force of 200 N is
applied over an area of 50 cm
2
?
1. 150 N/cm
2
2. 4 N/cm
2
correct
3. 10000 N/cm
2
4. 0.24 N/cm
2
Explanation:
Let : F = 200 N and
A = 50 cm
2
.
P =
F
A
=
200 N
50 cm
2
= 4 N/cm
2
.
004 10.0 points
Put the following heights in the order of air
density with the most dense point first:
A) Earth surface
B) low atmosphere (just above high moun-
tains)
C) high atmosphere (way above jet flights)
D) deep mine
E) the bottom of an imaginary hole drilled to
the center of the Earth
1. DACEB
2. ABDEC
3. EDABC correct
4. DAEBC
5. DACBE
6. ABDCE
Explanation:
The air filling up the mine adds weight and
pressure at the bottom of the mine, so the
density of air in a deep mine is greater than
that at the surface. (According to Boyle’s
law, greater pressure in a gas means greater
density.)
005 10.0 points
Fluids are
1. either liquids or gases. correct
2. liquids, gases, and solids.

mitchell (jm56986) – HW #9 – montgomery – (24131) 2
3. liquids.
4. either solids or gases.
Explanation:
006 10.0 points
If you mixed oil and vinegar in one container,
which would you expect to end up on top?