Test
Exam 3 Physics
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Preguntas del test (37)
1Objects A and B are at the same temperature. Object A now has its temperature increased by one fahrenheit degree, while B has its temperature increase by one kelvin degree. Which object now has a higher temperature?
- AObject A
- BObject B
- CBoth have the same temp
- DImpossible to tell from this data.
2a box of crackers is labeled " 120 calories per serving". Assuming this means 120 kcal, the energy of a serving of crackers is about?
- A120 J
- B4.2 x 10^3 J
- C5 x 10^4 J
- D5 x 10^5 J
3Four samples: Steel, Lead, Alcohol, and glass all have the same mass and are all initially at 20 degrees Celsius. After 100 calories of heat is added to each sample, the final temperatures are 38.2 celsius for Steel, 85.6 celsius for lead, 23.4 celsius for alcohol, and 30 celsius for glass. Which of these four samples has the largest specific heat capacity?
- ASteel
- BLead
- CAlcohol
- DGlass
- Eall the same
4The term Heat in physics is
- Aequivalent to temperature
- Bequivalent to internal energy
- Cany energy transferred to a body that raises the temperature of the body
- Denergy transferred to a body because of a difference in temperature
- Ethe same as work
5 Heat flows into a gas in a piston and the gas performs some work on its surroundings. The amount of work done is less than the head added. In this situation,
- Athe internal energy of the gas decreased.
- Bthe internal energy of the gas did not change.
- Cthe internal energy of the gas increased.
- Dthe gas experienced a phase change.
- Eenergy is not conserved and so it cannot happen.
6Hot cider is poured into a metal cup. Shortly hereafter the handle of the cup becomes hot. This is due to the process of
- Aconduction
- Bconvection
- Cradiation
- Dosmosis
7If you stand near a large fire, your face will be cooler if you place your hand between your face and the fire. Your hand is preventing heat flow by
- Aconduction
- Bconvection
- Cradiation
- Dlatent heat
8Whenever a gas is compressed,
- AWork must be done on the gas
- Bits internal energy mus get smaller
- Cheat must leave the gas
- Dthe temperature of the gas must get smaller
9Energy added to a cyclical heat engine
- Ais completely converted to external work
- Bis converted to increased internal energy in the engine plus external work
- Cis used to generate work that is greater than the added energy
- Dis converted to work and to waste heat
10The change in internal energy during one complete cycle of a heat engine
- Aequals the net heat flow into the engine
- Bequals zero
- Cequals the heat energy exhausted from the engine
- Dequals the heat energy entering the engine
11a correct statement of the 2nd Law of Thermodynamics is:
- Athe random motion of gas molecules will be decreased if energy is added to a gas
- Bthere is no process that can make heat flow from a cold object to a hot object
- Cno heat engine can have an efficiency greater than 30%
- Dheat will not flow spontaneously from a cold object to a hot object
12The overall direction of change in the universe is toward
- Aa state of increased mass in the universe
- Bincreased energy content of the universe
- Ca state of greater disorder
- Da state of increased orginization
13an ideal heat engine is operating between high and low temperature reservoirs. Suppose that now the low temperature reservoir has its temperature lowered, but no other changes are made. This temperature change affects the engine efficiency in the following way:
- Athe efficiency increases
- Bthe efficiency is unchanged
- Cthe efficiency decreases
- Dthere is no way to calculate the efficiency
14a heat engine having an efficiency of .20 takes in 2000J of energy from the hot reservoir in one cycle. In the same time, how much work will it perform?
- A0 J
- B400 J
- C1000 J
- D1600 J
- E10000 J
15A refrigerator transfers heat from a colder body to a hotter body while energy is used to operate the device. This is
- Aallowed only if the internal energy of the refrigerator increases
- Bconsistent with Clausius' statement of the second law.
- Cpossible if entropy of the contents of the refrigerator increases
- Dimpossible unless the refrigerator uses a Carnot cycle.
16A heat engine that would take in 1000 J of heat from a reservoir at 500 K and exhaust 500 J to a reservoir at 300 K, converting the other 500 J of heat to work, is
- Anot thermodynamically possible
- Bpossible only for a Carnot cycle
- Cthermodynamically possible
17If, for an ideal heat engine, Qh, Qc, and W are respectively, the heat absorbed, the heat rejected, and the work done per cycle, which of these is true?
- AQh cannot be more than Qc
- BQh cannot be more than W
- CW cannot be more than Qc
- DQc cannot be more than Qh
18An electron situated near another electron would feel
- Aa repulsive electrical force
- Ban attractive electrical force
- Ca repulsive magnetic force
- Dan attractive magnetic force
- ENo forces from the other electron
19Consider a proton and an electron placed near one another no other objects close by. They would
- Aaccelerate away from each other
- Bremain motionless
- Caccelerate towards each other
- Dbe pulled together at a constant speed
- Emove away from each other at a constant speed
20Two equal positive charges are near each other. If we increase the amount of charge on just one of them then,
- Athe larger charge feels a stronger electrical force and the other a weaker electrical force
- Bthe electric field points toward the larger charge
- Cthe strength of the electric force on both decreases
- Dthe electric field at the position of the smaller charge increases
21an atom has
- Ajust as many electrons as protons
- Bno neutrons in the nucleus
- Cmore protons than electrons
- Das many electrons as protons and neutrons combined
- Eat least 1 neutron
22a uniform electric field has a magnitude of 10 N/C and is directed upward. A charge brought into the field experiences a force of 5.0 N downward. The charge must be
- A+50 C
- B-50 C
- C+0.5 C
- D-0.5 C
- E-2.0 C
23a Charged comb attracts bits of neutral dust in the air. This happens because
- Athe dust grounds the comb
- Bthe dust becomes charged by induction
- Cthe dust becomes polarized
- Dthe dust is a good condutor
24If two metal balls each have a charge of -10^-6 C and the repulsive force between them is 1 N, how far apart are they?
- A9.0 mm
- B9.4 cm
- C0.9 m
- D9.4 m
25Two equal charges repel one another with a force of 4.0 x 10^-4 N when they are 10 cm apart. If they are moved until the separation is 2.5 cm, the repulsive force will be
- A0.25 x 10^-4 N
- B1.0 x 10^-4 N
- C4.0 x 10^-4 N
- D16 x 10^-4 N
- E64 x 10^-4 N
26Three equal negative charges are placed at three of the four corners of a square. The direction of the electric field at the remaining corner of the square is
- Aalong a side of the square toward one of the charges
- Balong a side of the square away from one of the charges
- Calong the diagonal connecting this corner and another charge, away from the other charge
- Dalong the diagonal connecting this corner and another charge, toward the other charge
- Eno direction, zero field
27A uniform electric field has a magnitude of 10 N/C and its directed upward. A charge brought into the field experiences a force of 5.0 downward. The charge must be
- A+50 C
- B-50 C
- C+0.5 C
- D-0.5 C
- E-2.0 C
28Archimedes Principle states that
- Athe pressure in a fluid is directly related to the depth below the surface of the fluid
- Ban object immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid
- Cthe pressure of a fluid is inversely proportional to the temperature of the fluid
- Dthe velocity of a fluid is directly proportional to the pressure exerted on the fluid
29a Balloon inflated with helium is able to float toward the ceiling because
- Athe weight of the balloon is greater than the weight of the air displaced by the baloon
- Bthe balloon and the gas it contains weigh less than the air displaced by the balloon
- Cthe density of the gas inside the balloon is greater than the density of the atmosphere
- Dthe pressure of the gas inside the balloon is greater than the atmospheric pressure
- Ethe pressure of the gas inside the balloon is less than the atmospheric pressure
30a child is drinking a liquid with a straw. Which of the following statements is true?
- AThe fluid is being pulled up into the straw
- Blonger straws work better because the pressure is larger deeper down
- Cthe pressure inside the straw depends on the viscosity of the liquid
- Dthe pressure in the straw is reduced and the liquid is pushed upwards by atmospheric pressure on the surface
31If you sit in a boat on the edge of a river channel, you might notice the water moving more quickly on the side away from the shore (the channel side). If you are initially moving with the river, you will be pushed
- Ainto the channel because the water pressure is larger on the shore side
- Binto the channel by the turbulent flow of the water
- Ctoward the shore because the water flow is laminar around the boat
- Dtoward the shore because the water pressure is smaller on the shore side
32If the atmospheric pressure is 15 lb/in^2, what is the corresponding downward force on the top of a horizontal square area 6 inches on each side?
- A540 lbs
- B90 lbs
- C15 lbs
- Dzero
33It is observed that as bubbles rise in a deep column of water, the diameter of the bubbles increases. This is best explained by
- ABernoulli's Principle
- BArchimede's Principle
- CBoyle's Law
- DPascal's Principle
34A hydraulic jack is used to lift a load of weight 5000 N. The load bearing cylinder has a radius of 5 cm, and and the other piston has a radius of 1 cm. What force must be exerted on the smaller piston to support the load?
- A100 N
- B200 N
- C1000 N
- D5000 N
- E25000 N
35a gas originally occupies a volume of 0.5 m^3 at a pressure of 100 Kpa. It is slowly allowed to expand until the volume is 2.5 m^3. Assuming the temperature is kept constant, the final pressure will be
- A10 kPa
- B20 kPa
- C50 kPa
- D100 kPa
- E500 kPa
36One section of a pipe carrying water has a cross sectional area of 20 cm^2, in this section the water has flow velocity of 1.0 m/s. Another section of this pipe has a constricted corss sectional area of 5 cm^2. If the flow is steady, what is the water velocity in the constricted section?
- A0.25 m/s
- B0.50 m/s
- C1.0 m/s
- D2.0 m/s
- E4.0 m/s
37According to Bernoulli's equation, the pressure in a fluid will tend to decrease if its velocity increases. Assuming that a wind speed of 1 m/s causes a pressure drop of .645 Pa, what pressure drop is predicted by Bernoulli's equation for a wind speed of 4 m/s?
- A10.35 Pa
- B2.58 Pa
- C1.94 Pa
- D1.29 Pa
Información
- Descripción
- Physics Test sobre Exam 3 Physics, creado por Beauregard Murphey el 10/11/2016.
- Autor
- Beauregard Murphey
- Idioma
- English
- Visitas
- 2
- Historial
- Creado el 10 nov 2016 · actualizado el 7 mar 2018
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