physics sem 1 final

17.12 Which process will double the power given off by a resistor?

Doubling the current by making a resistance half as big

15.1 Doug rubs a piece of fur on a hard rubber rod, giving the rod a negative charge. What happens?

Electrons are added to the rod

18.6 When a light bulb is turned on, its resistance increases until it reaches operating temperature. What happens to the current in the bulb as it is warming up?

It decreases.

17.3 If the current in a wire is tripled, what effect does this have on the electron drift velocity in the wire?

It triples.

Areas always have dimensions ____ while volumes always have dimensions ____.

L^2, L^3

(9.3.2) The quantity "pressure" expressed in terms of the fundamental quantities (mass, length, time) is equivalent to:

ML^-1T^-2

(12.1.1) The volume of an ideal gas changes from 0.40 to 0.55 m3 although its pressure remains constant at 50,000 Pa. What work is done on the system by its environment?

NEGATIVE 7500 J

(12.3.3) According to the second law of thermodynamics, which of the following applies to the heat received from a high temperature reservoir by a heat engine operating in a complete cycle?

cannot be completely converted to work

17.9 When a superconductor's temperature drops below the critical temperature, its resistance:

drops to zero.

15.2 Which of the following best characterizes electrical conductors?

electric charges move freely

16.3 The quantity of electrical potential, the volt, is dimensionally equivalent to:

electric field x distance

(12.1.3) Area on a P-V diagram has units associated with:

energy

(12.4.1) Which of the following choices best corresponds to what is required by the second law of thermodynamics for any process taking place in an isolated system?

entropy increases

15.7 The number of electric field lines passing through a unit cross sectional area is indicative of:

field strength

(10.3.3) A steel plate has a hole drilled through it. The plate is put into a furnace and heated. What happens to the size of the inside diameter of a hole as its temperature increases?

increases

(12.2.1) According to the first law of thermodynamics, the sum of the heat gained by a system and the work done on that same system is equivalent to which of the following?

internal energy change

16.6 At which location will the electric field between the two parallel plates of a charged capacitor be the strongest in magnitude?

midway between the two plates nearest their center

15.3 If body P, with a positive charge, is placed in contact with body Q (initially uncharged), what will be the nature of the charge left on Q?

must be positive

(10.2.1) Which best describes the relationship between two systems in thermal equilibrium?

no net energy is exchanged

(11.5.1) If one's hands are being warmed by holding them to one side of a flame, the predominant form of heat transfer is what process?

radiation

17.14 A light bulb with a tungsten filament is attached to a source of variable voltage. As the voltage is increased on the bulb,

the bulb's resistance increases.

Since 1983 the standard meter has been defined in terms of which of the following?

the distance light travels in a certain fraction of a second

If the displacement of an object, x, is related to velocity, v , according to the relation x = A v , the constant, A, has the dimension of which of the following?

time

If a is acceleration, v is velocity, x is position, and t is time, then which equation is NOT dimensionally correct?

v = a/t

Which expression is dimensionally consistent with an expression that would yield a value for time - 1 ?( v is velocity, x is distance, and t is time)

v/x

(12.2.2) If an ideal gas does positive work on its surroundings, we may assume, with regard to the gas:

volume increases

(12.2.3) A 2.0-mol ideal gas system is maintained at a constant volume of 4.0 L. If 100 J of heat is added, what is the work done on the system?

zero

16.1 An electron (charge -1.6 x 10-19 C) moves on a path perpendicular to the direction of a uniform electric field of strength 3.0 N/C. How much work is done on the electron as it moves 15 cm?

zero

Which point is nearest the x axis?

(5,-2)

(12.1.4) What is the work done on the gas as it expands from pressure P1 and volume V1 to pressure P2 and volume V2 along the indicated straight line?

(look closely!!) - (P1 + P2)(V2 - V1)/2

17.10 A 60-W light bulb is in a socket supplied with 120 V. What is the current in the bulb?

.50 A

(9.6.3) The bottom of a flat‑bottomed aluminum boat has area = 4.0 m2 and mass = 60 kg. If two fishermen and their fishing gear with total mass of 300 kg are placed in the boat, how much lower will the boat ride in the water? (H2O density = 1.0 x 103 kg/m3)

0.075 m

A cereal box has the dimensions of 0.19 m x 0.28 m x 0.070 m. If there are 3.28 feet per meter, then what is the volume of the box in cubic feet?

0.13 cubic feet

(11.2.3) A waterfall is 145 m high. What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s2, cw = 4 186 J/kg×°C)

0.34°C

16.8 Three capacitors of 1.0, 1.5, and 2.0 μF are connected in series. Find the combined capacitance.

0.46 μF

(10.3.4) An automobile gas tank is filled to its capacity of 15.00 gallons with the gasoline at an initial temperature of 10°C. The automobile is parked in the sun causing the gasoline's temperature to rise to 60°C. If the coefficient of volume expansion for gasoline is 9.6 x 10-4/C°, what volume runs out the overflow tube? Assume the change in volume of the tank is negligible.

0.72 gallons

(12.3.6) An 800-MW electric power plant has an efficiency of 30%. It loses its waste heat in large cooling towers. Approximately how much waste heat (in MJ) is discharged to the atmosphere per second?

1 900 MJ

16.7 A 0.25-μF capacitor is connected to a 400-V battery. Find the charge on the capacitor.

1.0 x 10^-4 C

Assume everyone in the United States consumes one soft drink in an aluminum can every two days. If there are 270 million Americans, how many tons of aluminum need to be recycled each year if each can weighs 1/16 pound and one ton = 2000 pounds?

1.5 million tons

16.4 A uniform electric field, with a magnitude of 600 N/C, is directed parallel to the positive x-axis. If the potential at x = 3.0 m is 1 000 V, what is the change in potential energy of a proton as it moves from x = 3.0 m to x = 1.0 m? (qp = 1.6 x 10-19 C)

1.9 x 10-16 J

15.4 If the distance between two point charges is tripled, the mutual force between them will be changed by what factor?

1/9

The prefixes which are abbreviated p, n, and G represent which of the following?

10^-12, 10^-9, and 10^9

A physics class in a large lecture hall has 150 students. The total mass of the students is about ______ kg.

10^4 kg

17.11 If a 500-W heater carries a current of 4.00 A, what is the voltage across the ends of the heating element?

125 V

(12.3.5) An electrical generating plant operates at a boiler temperature of 220°C and exhausts the unused heat into a nearby river at 19°C. If the generating plant has a power output of 800 megawatts (MW) and if the actual efficiency is 3/4 the theoretical efficiency, how much heat per second must be delivered to the boiler? (0°C = 273 K)

2 620 MW

17.2 A wire carries a steady current of 0.1 A over a period of 20 s. What total charge passes through the wire in this time interval?

2 C

The distance to the Andromeda Galaxy is estimated at about 2 x 106 light years. A light year is the distance traveled by light in one year; if the speed of light is 3 x 108 m/s, about how far is it from our galaxy to Andromeda? (1 year = 3.15 x 107 s)

2 x 10^22 m

16.9 A 10.0-μF capacitor is attached to a 20-V power supply. How much energy is stored in the capacitor?

2.0 x 10^-3 J

17.1 The current in an electron beam in a cathode‑ray tube is measured to be 70 µA. How many electrons hit the screen in 5.0 s? (e = 1.6 x 10-19 C)

2.2 x 10^15 electrons

16.2 A 9.0-V battery is connected between two parallel metal plates 4.0 mm apart. What is the magnitude of the electric field between the plates?

2.3 x 103 N/C

(10.3.6) Suppose the ends of a 20-m-long steel beam are rigidly clamped at 0°C to prevent expansion. The rail has a cross‑sectional area of 30 cm2. What force does the beam exert when it is heated to 40°C? (asteel = 1.1 x 10-5/C°, Ysteel = 2.0 x 1011 N/m2).

2.6 x 105 N

18.5 Three 8.0-Ω resistors are connected in parallel. What is their equivalent resistance?

2.7 Ω

(12.2.4) A closed 2.0-L container holds 3.0 mol of an ideal gas. If 200 J of heat is added, what is the change in internal energy of the system?

200 J

(9.3.1) The standard kilogram is a platinum‑iridium cylinder 39.0 mm in height and 39.0 mm in diameter. What is the density of the material?

21.5 g/cm^3

A triangle has sides of length 7.0 cm and 25 cm. If the triangle is a right triangle, which of the following could be the length of the third side?

24 cm

18.4 Three 8.0-Ω resistors are connected in series. What is their equivalent resistance?

24.0 Ω

(12.4.2) A 2.00-kg block of ice is at STP (0°C, 1 atm) while it melts completely to water. What is its change in entropy? (For ice, Lf = 3.34 ´ 105 J/kg)

2450 J/K

(10.3.5) A long steel beam has a length of twenty-five meters on a cold day when the temperature is 0°C. What is the length of the beam on a hot day when T = 40°C? (asteel= 1.1 x 10-5/C°)

25.011 m

17.7 A 20-Ω platinum wire at 20°C with a temperature coefficient of resistivity of 3.9 x 10-3 (°C)-1 will have what resistance at 100°C?

26 Ω

A furlong is a distance of 220 yards. A fortnight is a time period of two weeks. A race horse is running at a speed of 5.00 yards per second. What is his speed in furlongs per fortnight?

27 500 furlongs/fortnight

18.2 The two ends of a 3.0-Ω resistor are connected to a 9.0-V battery. What is the total power delivered by the battery to the circuit?

27 W

(9.6.1) A piece of aluminum has density 2.70 g/cm3 and mass 775 g. The aluminum is submerged in a container of oil (oil's density = 0.650 g/cm3). How much oil does the metal displace?

287 cm^3

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 10.5 x 8.8 x 3.14?

290

(10.4.1) An ideal gas is confined to a container with adjustable volume. The pressure and mole number are constant. By what factor will volume change if absolute temperature triples?

3.0

The two ends of a 3.0-Ω resistor are connected to a 9.0-V battery. What is the current through the resistor?

3.0 A

(10.3.2) A rectangular steel plate with dimensions of 30 cm x 25 cm is heated from 20°C to 220°C. What is its change in area? (Coefficient of linear expansion for steel is 11 x 10-6/C°.)

3.3 cm2

(9.5.1) What is the total force on the bottom of a 2.0-m-diameter by 1.0-m-deep round wading pool due to the weight of the air and the weight of the water? (Note the pressure contribution from the atmosphere is 1.0 x 105 N/m2, the density of water is 1 000 kg/m3, and g = 9.8 m/s2.)

3.4 x 10^5 N

17.6 A flashlight bulb operating at a voltage of 4.5 V has a resistance of 8.0 Ω. How many electrons pass through the bulb filament per second (e = 1.6 x 10-19 C)?

3.5 x 10^18

16.5 Find the electrical potential at 0.15 m from a point charge of 6.0 mC. (ke = 8.99 ´ 109 N×m2/C2)

3.6 x 10^5 V

15.6 Two point charges, separated by 1.5 cm, have charge values of +2.0 and -4.0 µC, respectively. What is the value of the mutual force between them? (ke = 8.99 x 109 N×m2/C2)

320 N

(12.3.1) A heat engine exhausts 3 000 J of heat while performing 1 500 J of useful work. What is the efficiency of the engine?

33%

A high fountain of water is in the center of a circular pool of water. You walk the circumference of the pool and measure it to be 150 meters. You then stand at the edge of the pool and use a protractor to gauge the angle of elevation of the top of the fountain. It is 55 ° . How high is the fountain?

34 m

Calculate (0.82 + 0.042) x (4.4 x 103), keeping only significant figures

3800

When NASA was communicating with astronauts on the moon, the time from sending on the Earth to receiving on the moon was 1.28 s. Find the distance from Earth to the moon. (The speed of radio waves is 3.00 x 108 m/s.)

384,000 km

The length and width of a standard sheet of paper is measured, and then the area is found by calculation to be 93.50 in2. The number of significant figures in the width measurement must be at least:

4

(11.2.2) A 10-kg piece of aluminum (which has a specific heat of 900 J/kg×°C) is warmed so that its temperature increases by 5.0 C°. How much heat was transferred into it?

4.5 × 10^4 J

(12.3.4) An electrical generating plant operates at a boiler temperature of 220°C and exhausts the unused heat into a nearby river at 18°C. What is the maximum theoretical efficiency of the plant? (0°C = 273 K)

41%

(12.3.7) A gasoline engine with an efficiency of 30.0% operates between a high temperature T1 and a low temperature T2 = 320 K. If this engine operates with Carnot efficiency, what is the high‑side temperature T1?

457 K

(9.2.2) A copper wire of length 2.0 m, cross sectional area 7.1 ´ 10-6 m2 and Young's modulus 11 ´ 1010 N/m2 has a 200-kg load hung on it. What is its increase in length? (g = 9.8 m/s2)

5.0 mm

17.8 A metal wire has a resistance of 25.00 Ω under room temperature conditions of 25°C. When the wire is heated to 85°C the resistance increases by 0.75 Ω. What is the temperature coefficient of resistivity of this metal?

5.0 x 10^-4 (°C)^-1

17.5 You measure a 25.0-V potential difference across a 5.00-Ω resistor. What is the current flowing through it?

5.00 A

On planet Z, the standard unit of length is the foose. Ann the Astronaut is 5.90 feet tall on earth. She lands on planet Z and is measured to be 94 foosi tall. Her partner Rachael is 88 foosi tall. How tall is Rachael on Earth?

5.5 ft

18.3 When a 24.0-Ω resistor is connected across a 12.0-V battery, a current of 482 mA flows. What is the power output delivered by the emf of the battery?

5.78 W

(10.3.1) A steel wire, 150 m long at 10°C, has a coefficient of linear expansion of 11 x 10-6/C°. Give its change in length as the temperature changes from 10°C to 45°C.

5.8 cm

18.7 EXTRA CREDIT: An electric car is designed to run off a bank of 12‑V batteries with total energy storage of 3.0 x 107 J. If the electric motor draws 6 000 W in moving the car at a steady speed of 10 m/s, how far will the car go before it is "out of juice?"

50 km

(11.3.1) A 120 g block of copper is taken from a kiln and quickly placed into a beaker of negligible heat capacity containing 300 g of water. The water temperature rises from 15C to 35C. Given cCu = 0.10 cal/gC, and cwater = 1.00 cal/gC, what was the temperature of the kiln?

535°C

(12.3.2) A heat engine operating between a pair of hot and cold reservoirs with respective temperatures of 500 K and 200 K will have what maximum efficiency?

60%

(9.5.2) A 15 000-N car on a hydraulic lift rests on a cylinder with a piston of radius 0.20 m. If a connecting cylinder with a piston of 0.040-m radius is driven by compressed air, what force must be applied to this smaller piston in order to lift the car?

600 N

Water flows into a swimming pool at the rate of 8.0 gal/min. The pool is 16 ft wide, 32 ft long and 8.0 ft deep. How long does it take to fill? (1 U.S. gallon = 231 cubic inches)

64 hours

(9.6.2) What volume of water is displaced by a submerged 2.0-kg cylinder made of solid aluminum? (aluminum density = 2.7 x 103 kg/m3 and water density = 1.0 x 103 kg/m3)

7.4 x 10^-4 m^3

(11.4.1) How much heat energy is required to vaporize a 1.0‑g ice cube at 0°C? The heat of fusion of ice is 80 cal/g. The heat of vaporization of water is 540 cal/g, and cwater = 1.00 cal/g×°C.

720 cal

17.13 A water pump draws about 3.8 A when connected to 240 V. What is the cost (with electrical energy at 9 cents per kWh) of running the pump for 10 h?

82 cents

A train slowly climbs a 500-m mountain track which is at an angle of 10.0 ° with respect to the horizontal. How much altitude does it gain?

86.8 m

15.5 If the size of the charge value is tripled for both of two point charges maintained at a constant separation, the mutual force between them will be changed by what factor?

9.0

(9.3.3) A stonecutter's chisel has an edge area of 0.50 cm2. If the chisel is struck with a force of 45 N, what is the pressure exerted on the stone?

900 000 Pa

Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 12.4 + 11 + 67.37 + 4.201?

95