mitchell (jm56986) – HW #9 – montgomery – (24131)
1
This
printout
should
have
20
questions.
Multiplechoice 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 130lb
woman wearing high heels.
correct
2.
Your bare foot was stepped on by a 270lb
man wearing flatsoled 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.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
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?
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '09
 montogomery
 Physics, Mitchell

Click to edit the document details