Section 2 Flashcards
______ are the smallest subdivision of matter that retains the chemical properties of a substance.
Atoms
Which of the following is not a mixture: a) granite; b) cake; c) air; d) beach sand; e) All of the above are mixtures.
e) All of the above are mixtures.
A force that determines the chemical properties of an atom is a(n)
electrical force.
Muller’s micrograph reveals: a) a peek at actual atoms; b) the position of atoms; c) x-ray patterns; d) All of the above.
b) the position of atoms.
An x-ray diffraction pattern of a solid indicates that the solid is
crystal.
A cup of water and a big tank of water, which one has higher density?
Both are the same.
The mass of a cubic meter of water is
1000 kg.
One liter of water has a mass of
1 kilogram.
A 10 cm long spring extends to 12 cm when a 1 kg load is suspended from it. What would be its length if a 3 kg load were suspended from it?
16 cm.
10 cm + 2 cm for 1 kg; add 2 kg more means
2 cm + 2 cm + 2 cm = 6 cm + original 10 cm = 16 cm
The shape that has the greatest strength in construction is the
triangle.
When you sit in the middle of a horizontal bench supported at its ends, the top side of the bench is
compressed and the bottom is stretched.
If Alice in Wonderland shrinks to one-tenth her size, the ratio of her surface area/volume will
increase.
Suppose you scale up a model machine by a factor of 4. Then its value is
64 times as much and its surface area is 16 times as much.
volume means ^3 so, 4^3 = 64
surface means ^2 so, 4^2 = 16
When you stand on one foot instead of two, the force you exert on the floor is
the same.
The force you exert on the floor is your weight, which stays the same.
When you stand on one foot instead of two, the pressure you exert on the floor is
more.
The pressure is force/area. The area of one foot is less than both feet, which means more pressure.
Pressure in air or water is: a) mass per area; b) weight per area; c) volume per area; d) density per area; e) energy per area.
b) weight per area.
Swim twice as deep, then the water pressure on you is
twice as much.
When holes are drilled through the wall of a water tower, water will spurt out the greatest horizontal distance from the hole closest to the
bottom of the tower.
Water pressure provided by a water tower is greater if the tower
is taller.
A dam is thicker at the bottom than at the top partly because
water pressure is greater with increasing depth.
Pumice is a volcanic rock that floats. Its density is: a) less than the density of water; b) equal to the density of water; c) more than the density of water.
a) less than the density of water.
What is the buoyant force acting on a 10 ton ship floating in the ocean?
10 tons.
A ship passed through a canal, and run from freshwater to saltwater, it will
float higher in saltwater and experience the same buoyant force.
Which would float highest in the water: a) Loading a boat with 30 tons of lead evenly spread across the surface; b) Loading a boat with 30 tons of lead concentrated in a small hold; c) Loading a boat with 40 tons of boxes filled with air stacked high; d) Loading a boat with 15 tons of lead boxes stacked high.
d) Loading a boat with 15 tons of lead boxes stacked high.
Ice floats because
ice is less dense than water.
When a given mass of water freezes, it undergoes a
increase in volume.
A completely submerged object always displaces its own
volume of fluid.
The reason a life jacket helps you float is
the density of both you and the jacket together is less than your density alone.
A 50 g wood block and a 50 g iron block submerged in water, which of them experiences a greater buoyant force?
Wood block.
The difference in the upward and downward forces acting on the submerged block is: a) getting bigger at deeper place; b) getting smaller at deeper place; c) the same at any depth; d) none of the above.
c) the same at any depth.
Why doesn’t the buoyant force on our bodies while we are standing in air cause us to float?
We weigh more than the weight of the air we displace.
If 10 kg load on small piston with surface area A, how many load can be lifted by a hydraulic piston with a surface area of 50 A: a) 5 kg; b) 50 kg; c) 500 kg; d) 5000 kg.
c) 500 kg.
10 kg x 50 kg = 500 kg
Bubbles are spherical for the reason of
surface tension.
The air in this room has: a) mass; b) weight; c) energy; d) all of these; e) none of these.
d) all of these.
Atmospheric molecules do not fly off into outer space because of
Earth gravitation.
Atmospheric pressure is caused by the
weight of the atmosphere.
Why don’t barometers use water instead of mercury?
Water can be used but the barometer will be too tall.
About how high can water be theoretically lifted by a vacuum pump at sea level: a) less than 10.3 m; b) more than 10.3 m; c) 10.3 m.
c) 10.3 m.
In drinking soda or water through a straw, we make use of: a) Atmospheric pressure; b) Bernoulli’s principle; c) Capillary action; d) Surface tension.
a) Atmospheric pressure.
A piston in an airtight pump is withdrawn so that the volume of the air chamber is increased 3 times. What is the change in pressure: a) The pressure is 3 times the original pressure; b) The pressure is 1/3 the original pressure; c) The pressure does not change; d) There is not enough information to figure this out.
b) The pressure is 1/3 the original pressure.
pV = Pv
A balloon is buoyed up with a force equal to the
weight of air it displaces.
A one-ton blimp hovers in the air. The buoyant force acting on it is
one ton.
As a high-altitude balloon sinks lower and lower into the atmosphere, it undergoes a decrease in
volume.
A bubble of air released from the bottom of a lake: a) becomes larger as it rises; b) alternately expands and contracts as it rises; c) becomes smaller as it rises; d) rises to the top at constant volume.
a) becomes larger as it rises.
As a helium-filled balloon rises in the air, it becomes
less dense.
The faster a fluid moves, the: a) greater its internal pressure; b) less its internal pressure; c) internal pressure is unaffected.
b) less its internal pressure.
If water flows into a smaller diameter pipe and speeds up, the bubbles in the water: a) shrink; b) flatten; c) expand; d) wink.
c) expand.
When you pass a speeding truck on a highway, your car’s pull toward the truck is explained by: a) Bernoulli’s Principle; b) Archimedes Principle; c) Boyle’s Law.
a) Bernoulli’s Principle.
If you are standing in a cave on a cliff, and the air outside the cave is moving much faster than the air inside the cave, the pressure difference
wants to push you out of the cave.
The most common state of matter in the universe is
plasma.
