QUESTIONS WITH COMPLETE
SOLUTIONS
What is the relationship between mass, volume, and density? - ANSWERSDensity is
proportional to mass and inversely proportional to volume.
What is the relationship between area, force, and pressure? - ANSWERSPressure is
proportional to force and inversely proportional to area
Consider three drinking glasses. All three have the same base area, and all three are
filled to the same depth with water. Glass A is cylindrical. Glass B is wider at the top
than at the bottom, so it holds more water than glass A. Glass C is narrower at the top
than the bottom, so it holds less water than glass A. Which glass has the greatest liquid
pressure at the bottom? - ANSWERSAll three glasses have equal pressure at the
bottom.
What is the difference between the pressures inside and outside a bicycle tire called? -
ANSWERSgauge pressure
A jar is completely filled with water, and then it is sealed with a lid. If you push down on
the lid with a pressure of 1000 Pa, what happens to the water pressure at the bottom of
the jar? - ANSWERSThe water pressure at the bottom of the jar will increase by 1000
Pa.
A piece of wood is floating in a tub of water. A second piece of wood rest on top of the
first piece; it does NOT touch the water. If the second piece is removed from the first
and placed in the water, what happens to the water level in the tub? - ANSWERSThe
water level remains unchanged.
Bernoulli's principle can be used to explain the lift force on an airplane wing. How must
an airplane's wing be designed to ensure that Bernoulli's principle is applicable? -
ANSWERSAirplane wings must be designed to ensure that air molecules move more
rapidly over the top surface of the wing, creating a region of lower pressure.
Water flows through a horizontal pipe. The diameter of the pipe at point B is larger than
the diameter of the pipe at point A. Where is the speed of the water the greatest? -
ANSWERSThe speed of the water is the greatest at point A.
, Water flows through a horizontal pipe. The diameter of the pipe at point B is larger than
the diameter of the pipe at point A. Where is the water pressure the greatest? -
ANSWERSThe water pressure is the greatest at point B.
A cube of wood is floating on water. A cube of iron is totally submerged in water. The
cubes are equal in volume. Which cube has the greater buoyant force acting on it? -
ANSWERSThe cube of iron has the greater buoyant force acting on it.
Which temperature scale does NOT have negative values? - ANSWERSKelvin
temperature scale
A flat metal washer is heated. As the washer's temperature increases, what happens to
the hole in the center? - ANSWERSThe hole in the center of the washer will expand.
By which primary heat transfer mechanism does one end of a steel rod become hot
when the other end is placed in a flame? - ANSWERSconduction
By which primary heat transfer mechanism does a stove heat a pot of soup? -
ANSWERSconvection
By which primary heat transfer mechanism does the Sun warm Earth? -
ANSWERSradiation
If the pressure acting on a given sample of an ideal gas at constant temperature is
tripled, what happens to the volume of the gas? - ANSWERSThe volume is reduced to
one-third of its original value
If you calculate the thermal power radiated by typical objects at room temperature, you
will find surprisingly large values, several kilowatts typically. For example, a square box
that is 1 m on each side and painted black (therefore justifying an emissivity e near
unity) emits 2.5 kW at a temperature of 20∘C. In reality the net thermal power emitted by
such a box must be much smaller than this, or else the box would cool off quite quickly.
Which of the following alternatives seems to explain this conundrum best? -
ANSWERSThe surrounding room is near the temperature of the box and radiates about
2.5 kW of thermal energy into the box.
If both the pressure and volume of a given sample of an ideal gas are doubled, what
happens to the temperature of the gas in Kelvins? - ANSWERSThe temperature of the
gas in increased by four times its original value.
This pV diagram shows three possible paths for changing a system from an initial state,
represented by point 1, to a final state, represented by point 2. For which path is the
work done by the system the greatest? - ANSWERS1->3->2