Physical Science - Chapter 13

*As a liquid is added to a beaker, the pressure exerted by the liquid on the bottom of the beaker ____________________.

increases

*The unit g/cm3 is often used to express ____________________.

density

*Which of the following statements is true about an airplane wing during flight? a. Air above the wing travels faster than air below the wing. b. Air below the wing travels faster than air above the wing. c. The wing exerts pressure equally in all directions. d. The lift acting on the wing reduces the weight of the wing.

a. Air above the wing travels faster than air below the wing.

*The relationship between buoyant force and weight of a displaced fluid was first stated by a. Archimedes. b. Bernoulli. c. Newton. d. Pascal.

a. Archimedes Archimedes principle - a body immersed in a fluid is buoyed up by a force (buoyant force) equal to the weight of the fluid displaced by the body.

*The weight of an object that sinks in a fluid is ____________________ than the buoyant force acting on it.

greater

*A device that uses pressurized fluids acting on pistons of different sizes to change a force is called a(an) ____________________

hydraulic system

*A pascal, the SI unit of pressure is equal to 1 Newton per __________.

meters squared

*As the speed of a fluid increases, the ________ within the fluid decreases

pressure This is Bernouilli's Principle

*The direction of the buoyant force on an object placed in a fluid is ____________________.

upward The pressure in a fluid is exerted upward

*If you use a spring scale to measure the weight of a submerged object that has neutral buoyance, what will the scale read?

zero

*A brick weighs 28 N. Measured underwater, it weights 15 N. What is the size of the buoyant force exerted by the water on the brick?

13 N 28N - 15N = 13 N

*A pressure of 70 N/m2 equals what?

70 Pa

The height of anything above a given planetary reference plane, especially above sea level on earth is ____________.

Altitude

*What is Newton's First Law?

An object in motion stays in motion unless acted on by an outside force. An object at rest stays at rest unless acted on by an outside force

*The downward force produced when air flows over the winglike spoiler on a race car is an example of ____________________ principle.

Bernoulli's

*What is Newton's Third Law?

For every action there is an equal and opposite reaction.

*What is Newton's Second Law?

Force = Mass x Accleration (F=ma)

A body of coherent matter, usually of indefinite shape and often of considerable size is ___________.

Mass

The formula Force/Area is used to calculate

Pressure force divided by surface area (P=F/SA) Pressure = the exertion of force upon a surface by an object, fluid, etc. in contact with it.

Any force that counteracts the force of gravity.

Upward Force

The amount of space, measured in cubic units, that an object or substance occupies is ___________.

Volume

A water balloon can explode if squeezed tightly between two hands. Just prior to exploding, at what point of the balloon is the pressure exerted by the water greatest? a. It's greatest at the top of the balloon (point furthest from the ground). b. It's greatest at the bottom of the balloon (point nearest the ground). c. It's greatest at the points of contact between the balloon and the two hands. d. The pressure exerted by the water is the same at all points of the balloon.

a. It's greatest at the top of the balloon (point furthest from the ground). (if you squeeze the middle, the pressure will increase equally everywhere within the balloon.)

*The upward force acting on an object submerged in a fluid is called a. buoyant force. b. drag. c. pressure. d. weight

a. buoyant force.

*The pressure of a fluid at a specific depth a. depends only on the type of fluid. b. is exerted only in the downward direction. c. varies with the total volume of the fluid. d. all of the above.

a. depends only on the type of fluid.

*A cork is floating in salty water. As more salt is added to the water to increase its density, the cork will a. float at a higher level in the water. b. float at a lower level in the water. c. sink. d. float at the same level in the water.

a. float at a higher level in the water

When the buoyant force is equal to the weight of an object it a. floats or is suspended b. sinks

a. floats or is suspended

* Which exerts greater pressure on the floor, standing flat-footed or standing on tip-toes? a. on tip-toe because the force acts over less area b. on tip-toe because the force acts over more area c. flat footed because the force acts over more area d. flat footed because the force acts over less area

a. on tip-toe because the force acts over less area Pressure = Force/Surface Area

If an object is more dense than the fluid it is in, it will a. sink b. float

a. sink

*A ball is floating partially submerged in a liquid. The buoyant force acting on the ball equals the a. volume of the ball below the surface. b. volume of the ball above the surface. c. mass of the ball. d. weight of the ball.

a. volume of the ball below the surface Archimede's Principle: Buoyant Force = Weight of the FLUID displaced by the object A FULLY SUBMERGED object displaces a volume of fluid equal to its own volume A FLOATING object displaces a volume of fluid equal to the volume of the part of the object that is submerged

*Pressure is the result of force distributed over an ___________.

area

A gymnast standing on one hand (area .02 m2) pushes down on the ground with a force of 600 N. How much pressure does the gymnast exert on the ground? a. 3,000 Pa b. 30,000 Pa c. 12 Pa d. 1200 Pa

b. 30,000 Pa Pressure = Force/Surface Area 600 N/.02 m2 = 30,000 Pa

*Which of the following states Bernoulli's principle? a. As the speed of a fluid decreases, the pressure within the fluid decreases. b. As the speed of a fluid increases, the pressure within the fluid decreases. c. As the speed of a fluid changes, the pressure of the fluid remains constant. d. none of the above

b. As the speed of a fluid increases, the pressure within the fluid decreases.

*Two identical test tubes are filled with equal volumes of water and mercury. Which of the following statements is true? a. The weight of both liquids is the same. b. The bottom area of both test tubes is the same. c. The pressure at the bottom of both test tubes is the same. d. All of the above.

b. The bottom area of both test tubes is the same. - The weight is not the same because Mercury is more dense than water - The test tubes are identical, so the bottom area would be the same - The pressure at the bottom of each test tube would be different because Mercury is more dense and the force created would be greater than the force of water. Pressure = Force/Surface Area.

*Which of the following is NOT possible? a. compressing 10 liters of oxygen gas into a 1-liter volume b. compressing 2 liters of water into a 1-liter volume c. filling a balloon using helium gas from a pressurized tank d. allowing 5 liters of compressed air to expand to a volume of 100 liters

b. compressing 2 liters of water into a 1-liter volume

Which of the following materials is NOT a fluid? a. air b. cork c. gasoline d. water

b. cork

If an object is less dense than the fluid it is in, it will a. sink b. float

b. float

The hydraulic system of a dump truck is designed to multiply a. distance. b. force. c. pressure. d. speed.

b. force

*In order to calculate pressure exerted on a surface, what quantity is divided by surface area? a. altitude b. force c. mass d. volume

b. force force is the strength or power exerted upon an object Pressure = Force/Surface Area

*The upward force acting on the wing of an airplane in flight is called a. drag. b. lift. c. thrust. d. weight.

b. lift

When the buoyant force is less than the weight of an object, the object a. floats or is suspended b. sinks

b. sinks

*Atmospheric pressure is caused by a. air currents. b. the weight of the atmosphere above a particular location. c. clouds. d. the altitude above sea level.

b. the weight of the atmosphere above a particular location.

*The apparent loss of weight of an object in a fluid is called ____________________.

buoyancy buoyancy is an example of an upward force

*Even a rock at the bottom of a lake has a(an) _______________ force acting upward on it

buoyant

A 10,000-N ship is floating in the Great Salt Lake, whose salty water is denser than pure water. What is the buoyant force acting on the ship? a. 1000 N b. 8000 N c. 10,000 N d. 12,000 N

c. 10,000 N If an object floats, the buoyant force equals the object's weight. If the object sinks, the objects weight is greater than the buoyancy force.

The pressure of air at sea level is approximately a. 0 kPa. b. 10 kPa. c. 101 kPa. d. 1000 kPa.

c. 101 kPa.

*Where is fluid pressure greatest? a. 30 centimeters below the surface of a swimming pool b. 1 meter below the surface of a swimming pool c. 2 meters below the surface of a swimming pool d. The pressure is the same in all parts of a swimming pool

c. 2 meters below the surface of a swimming pool (water pressure increases as depth increases which is why scuba divers must descent slowly)

A 5-N input force of a hydraulic system corresponds to a 40-N output force. If the area of the small piston is 11 cm2, what is the area of the large piston? a. 8 cm b. 255 cm c. 88 cm d. 2200 cm2

c. 88 cm 5/11=40/x cross mulitiply. 440=5x x = 88

*An unknown substance is suspended in water. What can be concluded about the substance's density? a. The substance's density is greater than water's density. b. The substance's density is less than water's density. c. The substance's density is equal to water's density. d. Nothing can be concluded about the substance's density.

c. The substance's density is equal to water's density. - If the substance's density was greater than the water's density it would sink - If the substance's density was less than the water's density it would completely float - Since the substance is suspended in the water, it can be said that the substance's density is equal to the water's density.

*The strength of the buoyant force acting on an object in a fluid depends on the object's a. mass. b. surface area. c. volume. d. weight.

c. volume.

*In a hydraulic lift system, the fluid pressure exerted throughout the system is ____________________.

constant

If the air inside a balloon exerts a force of 1.5 N on an area of .5 m2, what is the pressure inside the balloon? a. .5 N/m2 b. 1.5 N/m2 c. 2.5 N/m2 d. 3 N/m2

d. 3 N/m2 Pressure = Force/Surface Area 1.5/.5 = 3

*Two identical corks float in separate beakers. One beaker contains distilled water. The other contains very salty water. Which of the following statements is true? a. The corks float at the same level in both liquids. b. The cork in the very salty water floats at a lower level than the other cork. c. The corks will eventually sink. d. Both corks are subject to the same buoyant force.

d. Both corks are subject to the same buoyant force.

*The operation of a hydraulic lift system is explained by a. Archimedes' principle. b. Bernoulli's principle. c. Newton's principle. d. Pascal's principle.

d. Pascal's principle

*Which principle states that a change in the pressure at any point in a fluid in a closed container is transmitted equally and unchanged in all directions throughout the fluid? a. Archimedes' principle b. Bernoulli's principle c. Newton's principle d. Pascal's principle

d. Pascal's principle

*Where will the greatest increase in pressure occur if you squeeze the middle of an upright, closed soft-drink bottle? a. The greatest increase in pressure will occur at the top of the bottle. b. The greatest increase in pressure will occur in the middle of the bottle. c. The greatest increase in pressure will occur on the bottom of the bottle. d. The pressure will increase equally everywhere within the bottle.

d. The pressure will increase equally everywhere within the bottle.

*Why does a hot-air balloon float? a. The shape of the balloon provides lift. b. The volume of the air displaced by the balloon is less than the volume of the balloon. c. The weight of the air displaced is less than the volume of the balloon. d. The weight of the balloon is less than the weight of the air displaced by the balloon.

d. The weight of the balloon is less than the weight of the air displaced by the balloon.

*The buoyant force on an object in a fluid is equal to the weight of the a. fluid b. fluid surrounding the object c. fluid displaced by the object d. object

d. object

*What is the SI Unit of Pressure? a. g/cm3 b. m/s2 c. the newton d. the pascal

d. the pascal The pascal is equal to 1 Newton per meters squared

*As you climb a high mountain, the buoyant force exerted on you by the atmosphere ____________________.

decreases As altitude increases, air pressure decreases

*As your altitude increases, air pressure ____________________.

decreases this is why mountain climbers on very high peaks need cylinders of oxygen as the approach the top. The pressure of air decreases the higher in altitude they go.

*A submerged submarine alters its ____________________ to rise or fall in the water.term-61

density An object that is more dense will sink An object that is less dense will float The submarine will make its density greater to fall in the water and will make it less to rise.

*The pressure exerted by a fluid at any given depth is exerted ____________________ in all directions.

equally

*A substance that flows and assumes the shape of its container is a(an)

fluid

The strength or power exerted upon an object is _________.

force