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Preguntas del test (64)
1(True or false) For Kepler's law of equal areas to be valid, the force of gravity must vary inversely with the square of the distance between a given planet and the sun.
- AVerdadero
- BFalso
2(True or False) The planet closest to the Sun has the shortest orbital period.
- AVerdadero
- BFalso
3(True or False) Venus's orbital speed is larger than the orbital speed of Earth.
- AVerdadero
- BFalso
4(True or false) The orbital period of a planet allows accurate determination of that planet's mass
- AVerdadero
- BFalso
5If the mass of a small Earth-orbiting satellite is doubled, what must happen for the radius of its orbit to remain constant?
- AThe speed of the satellite must double
- BThe speed of the satellite must decrease by half
- CThe speed of the satellite must increase slightly
- DThe speed of the satellite must remain unchanged
6During which season in the northern hemisphere does Earth attain its maximum orbital speed about the Sun?
- ASpring
- BWinter
- CAutumn
- DSummer
7In what season does it attain its minimum orbital speed?
- AWinter
- BSpring
- CSummer
- DAutumn
8In which years of the twentieth century was Halley's Comet traveling at its fastest orbital speed about the Sun?
- A1901 and 1975
- B1911 and 1987
- C1925 and 2001
- D1935 and 1999
9Halley's Comet is in a highly elliptical orbit about the Sun with a period of approximately 76 years. Its last closest approach to the Sun occurred in 1987. In what years of the twentieth century was it traveling about the Sun at its slowest orbital speed?
- A1923 and 1999
- B1911 and 1987
- C1949 and 1973
- D1935 and 1961
10Venus has no natural satellites, but artificial satellites have been placed in orbit around it. To determine the mass of Venus using one of these satellites, what orbital parameters would you need to measure, and how would you use these parameters for the calculation?
- AMeasure the satellite's speed and distance from Venus; use
𝑣
=
𝐺
𝑀
𝑟
v=
r
GM
to calculate Venus's mass. - BMeasure the satellite's orbital period and distance from Venus; use
𝑇
2
=
4
𝜋
2
𝑟
3
𝐺
𝑀
T
2
=
GM
4π
2
r
3
to calculate Venus's mass. - CMeasure the satellite's acceleration and its distance from Venus; use
𝑎
=
𝐺
𝑀
𝑟
2
a=
r
2
GM
to calculate Venus's mass. - DMeasure the satellite's temperature and distance from Venus; use
𝑇
∝
𝑀
𝑟
2
T∝
r
2
M
to calculate Venus's mass.
- AMeasure the satellite's speed and distance from Venus; use
11(True or false) A majority of the asteroids are in approximately circular orbits in a "belt" between Mars and Jupiter. All these asteroids have the same orbital period about the Sun.
- AVerdadero
- BFalso
12At 4 times the Moon's radius, the acceleration due to gravity is
- AThe same as at the Moon's surface
- BHalf of the surface gravity.
- COne-sixteenth of the surface gravity.
- DOne-fourth of the surface gravity.
13At half the radius of Earth, the acceleration due to gravity is approximately
- AThe same as at Earth's surface
- BFour times the surface gravity.
- COne-fourth the surface gravity.
- DTwice the surface gravity.
14If both star masses are doubled, what must happen to their distance to maintain the same gravitational force?
- AThe distance must be halved.
- BThe distance must be doubled.
- CThe distance must remain the same.
- DThe distance must decrease by a factor of square root 2.
15What unique location exists between Earth and the moon where a spaceship is truly weightless?
- AThe Moon's surface.
- BEarth's atmosphere.
- CThe center of mass of the Earth-Moon system.
- DThe Lagrange point where Earth's and the Moon's gravitational forces cancel each other.
16Is the unique weightless location between Earth and the moon closer to the moon, midway, or closer to Earth?
- Acloser to the moon
- Bmidway
- Ccloser to earth
17Why is the weightless location between Earth and the moon closer to the moon?
- ABecause the Moon has a stronger gravitational pull than Earth.
- BBecause the Earth’s gravitational pull is weaker due to its larger distance.
- CBecause the Moon’s mass is smaller, requiring the balance point to be closer to it.
- DBecause the gravitational forces do not depend on the masses of Earth and the Moon.
18Suppose the escape speed from a planet is only slightly larger than the escape speed from Earth, yet the planet is considerably larger than Earth. How would the planet’s (average) density compare to Earth’s (average) density?
- AThe planet’s density is significantly greater than Earth’s density.
- BThe planet’s density is the same as Earth’s density.
- CThe planet’s density is slightly greater than Earth’s density.
- DThe planet’s density is smaller than Earth’s density.
19Suppose that, using a telescope in your backyard, you discovered a distant object approaching the Sun, and were able to determine both its distance from the Sun and its speed. How would you be able to predict whether the object will remain “bound” to the solar system, or if it is an interstellar interloper that would come in, turn around, and escape, never to return?
- ABy comparing its speed to the escape speed at that distance from the Sun.
- BBy calculating its orbital period and checking if it is elliptical.
- CBy measuring its mass and comparing it to the mass of the Sun.
- DBy observing the object’s light curve to determine its trajectory.
20During a trip back from the moon, the Apollo spacecraft fires its rockets to leave its lunar orbit. Then, it coasts back to Earth where it enters the atmosphere at high speed, survives a blazing reentry, and parachutes safely into the ocean. In what direction do you fire the rockets to initiate this return trip? Explain the changes in kinetic energy, gravitational potential, and total mechanical energy that occur to the spacecraft from the beginning to the end of this journey.
- AThe rockets should be fired in the direction opposite to the spacecraft's velocity. The spacecraft's kinetic energy decreases, gravitational potential energy decreases, and total mechanical energy remains constant.
- BThe rockets should be fired in the direction of the spacecraft's velocity. The spacecraft’s kinetic energy increases, gravitational potential energy increases, and total mechanical energy remains constant.
- CThe rockets should be fired in the direction opposite to the spacecraft's velocity. The spacecraft's kinetic energy decreases, gravitational potential energy increases, and total mechanical energy remains constant.
- DThe rockets should be fired in the direction opposite to the spacecraft's velocity. The spacecraft’s kinetic energy increases, gravitational potential energy increases, and total mechanical energy decreases.
21Why is the gravitational field inside a solid sphere of uniform mass directly proportional to the distance from the center (r) rather than inversely proportional to r?
- ABecause the mass of the sphere outside the radius r does not contribute to the gravitational field at that point.
- BBecause the gravitational field inside a sphere decreases as the distance from the center increases.
- CBecause the gravitational field inside a uniform sphere behaves like that of a point mass located at the center.
- DBecause only the mass inside the radius r contributes to the gravitational field, and it increases with r.
22(True or False) F = 0 is sufficient for static equilibrium to exist.
- AYes, because a net force of zero ensures that there is no motion.
- BNo, because in addition to a net force of zero, the net torque must also be zero.
- CYes, because static equilibrium only requires that forces balance out.
- DNo, because the object must be in motion for static equilibrium to be true.
23(True or False) F = 0 is necessary for static equilibrium
- ATrue, because the object must have no net force acting on it for static equilibrium.
- BFalse, because static equilibrium can exist even with a non-zero net force.
- CTrue, because a net force of zero ensures that the object remains in place.
- DFalse, because static equilibrium requires a non-zero net force to remain at rest.
24(True or False) An object in equilibrium cannot be moving.
- ATrue, because equilibrium means the object is at rest and cannot move.
- BFalse, because an object in equilibrium can be moving at a constant velocity.
- CTrue, because objects in equilibrium must always be stationary.
- DFalse, because equilibrium only applies to stationary objects.
25(True or False) The center of gravity is always at the geometric center of a body.
- ATrue, because the center of gravity is always located at the center of mass.
- BFalse, because the center of gravity depends on the distribution of mass and may not be at the geometric center.
- CTrue, because the center of gravity is the point where the object balances.
- DFalse, because the center of gravity is always at one of the edges of the object.
26(True or False) The center of gravity must be located inside an object.
- ATrue, because the center of gravity is always within the object.
- BFalse, because the center of gravity can be located outside the object if its mass distribution is asymmetrical.
- CTrue, because the center of gravity is the point where the object balances.
- DFalse, because the center of gravity is always at the geometric center of the object.
27(True or False) The center of gravity of a baton is located between the two ends.
- AVerdadero
- BFalso
28(True or False) The torque produced by the force of gravity about the center of gravity is always zero.
- AVerdadero
- BFalso
29What happens to your center of gravity when you try to stand up without leaning?
- AIt moves higher and remains directly above your feet.
- BIt moves lower to increase stability.
- CIt stays in the same position as when sitting.
- DIt moves forward, making it harder to balance.
30A father (mass M) and his son (mass m) walk out toward opposite ends of a balanced see-saw. As they walk, the see-saw stays exactly horizontal. What can be said about the relationship between the father’s speed V and the son’s speed?
- AThe father’s speed is less than the son’s speed.
- BThe father’s speed is greater than the son’s s
- CThe father’s speed is equal to the son’s speed.
- DThe father’s speed is zero, and only the son moves.
31Travel mugs that people might set on the dashboards of their cars are often made with broad bases and relatively narrow mouths. Why would travel mugs be designed with this shape, rather than have the roughly cylindrical shape that mugs normally have?
- AA broad base improves stability, reducing the risk of tipping over.
- BA narrow mouth allows for better insulation, keeping drinks hotter for longer
- CA narrow mouth prevents spills when the mug is tipped over.
- DA broad base makes it easier to carry the mug with one hand.
32If the gauge pressure is doubled, what happens to the absolute pressure?
- AIt doubles.
- BIt increases by less than double.
- CIt stays the same.
- DIt increases by more than double.
33Two spherical objects differ in size and mass. Object A has a mass that is eight times the mass of object B. The radius of object A is twice the radius of object B. How do their densities compare?
- AThe density of object A is twice the density of object B. D2a>Db
- BThe density of object A is the same as the density of object B. Da=Db
- CThe density of object A is half the density of object B. Da<Db
- DThe density of object A is one-fourth the density of object B.D1/4a<Db
34Two objects differ in density and mass. Object A has a mass that is eight times the mass of object B. The density of object A is four times the density of object B. How do their volumes compare?
- AThe volume of object A is twice the volume of object B.
- BThe volume of object A is half the volume of object B.
- CThe volume of object A is the same as the volume of object B.
- DThe volume of object A is one-fourth the volume of object B
35A sphere is constructed by gluing together two hemispheres. The density of each hemisphere is uniform, but the density of one is greater than the density of the other. (True or false) The sphere's average density is the numerical average of the two different densities.
- AVerdadero
- BFalso
36what is the water pressure at a depth of 15m?(Assume density of water is 1000kg/m^3 and atmospheric pressure at the surface is 101,325 Pa)
- A147,150Pa
- B248,475Pa
- C101,325Pa
- D350,000Pa
37Why can't humans breathe through a reed at a depth of 15 meters underwater?
- AThe reed cannot reach the surface of the water.
- BThe high water pressure at that depth prevents the lungs from expanding enough to draw air.
- CThe reed does not provide enough oxygen.
- DThe air in the reed is compressed to a point where it is unusable.
38Two objects are balanced with identical volumes but different masses. Assume all objects are denser than water, so none will float. Will the equilibrium be disturbed if the entire system is completely immersed in water?
- AYes, because the buoyant force acting on each object will be different due to their different masses.
- BNo, because the buoyant force will be the same for both objects since they have identical volumes.
- CYes, because water pressure will cause one object to sink more than the other.
- DNo, because the system will be unaffected by immersion in water
39A solid 200-g block of lead and a solid 200-g block of copper are completely submerged in an aquarium filled with water. Each block is suspended just above the bottom of the aquarium by a thread. What is true about the two blocks?
- AThe lead block experiences a greater buoyant force because it is denser than the copper block.
- BThe copper block experiences a greater buoyant force because it displaces more water than the lead block.
- CBoth blocks experience the same buoyant force because they have the same mass.
- DThe lead block is suspended with less tension in the thread compared to the copper block.
40A 20 cm^3 block of lead and a 20 cm^3 block of copper are completely submerged in an aquarium filled with water. Each is suspended just above the bottom of the aquarium by a thread. Which of the following is true?
- AThe lead block experiences a greater buoyant force because it is denser than the copper block.
- BThe copper block experiences a greater buoyant force because it displaces more water than the lead block.
- CBoth blocks experience the same buoyant force because they have the same volume.
- DThe lead block is suspended with more tension in the thread compared to the copper block.
41Two bricks are completely submerged in water. Brick 1 is made of lead and has rectangular dimensions of 2 x 4 x 8 cm. Brick 2 is made of wood and has rectangular dimensions of 1 x 8 x 8 cm. Which statement is true regarding the buoyant force acting on the two bricks?
- AThe buoyant force on Brick 2 is larger than the buoyant force on Brick 1 because Brick 2 has a larger volume.
- BThe buoyant force on Brick 1 is larger than the buoyant force on Brick 2 because Brick 1 is made of lead.
- CBoth bricks experience the same buoyant force because they have the same dimensions.
- DThe buoyant force on Brick 1 and Brick 2 are equal because they are both submerged in water.
42Why does a person floating in water oscillate up and down while breathing?
- AThe person’s body mass increases when they breathe in, causing them to sink.
- BThe volume of air in the lungs changes with breathing, affecting the person’s buoyancy.
- CThe person’s heart rate increases when they inhale, causing them to rise in the water.
- Dhe person moves due to muscle contractions while breathing, causing them to float higher
43An object has a density just slightly less than that of water, so it floats almost completely submerged. However, the object is more compressible than water. What happens if the floating object is given a slight downward push?
- AThe object will remain in place, as its compressibility does not affect its buoyancy.
- BThe object will sink deeper into the water, but eventually return to its original position.
- CThe object will sink deeper into the water and stay there due to its greater compressibility.
- DThe object will rise to the surface even further due to the downward push.
44What happens to the speed of fluid as it enters the narrow part of a pipe?
- AThe speed of the fluid decreases.
- BThe speed of the fluid remains the same.
- CThe speed of the fluid increases.
- DThe fluid comes to a complete stop.
45What causes the fluid to accelerate into the narrow part of the pipe?
- AThe pressure in the narrow section is higher than in the wider section.
- BThe fluid experiences an increase in volume as it enters the narrow section.
- CThe fluid must conserve mass, so its velocity increases when the pipe narrows.
- DThe fluid is subjected to external forces that push it into the narrow section.
46You are sitting in a boat floating on a very small pond. You take the anchor out of the boat and drop it into the water. Does the water level in the pond rise, fall, or remain the same? Explain your answer.
- AThe water level rises.
- BThe water level falls.
- CThe water level remains the same.
- DThe water level initially rises and then falls.
47A horizontal pipe narrows from a diameter of 10 cm at location A to 5.0 cm at location B. For a nonviscous incompressible fluid flowing without turbulence from location A to location B, how do the flow speeds 𝑣 (in m/s) compare at the two locations?
- AThe flow speed at location A is faster than at location B.
- BThe flow speed at location A is slower than at location B.
- CThe flow speed at location A is equal to the flow speed at location B.
- DThe flow speed at both locations depends on the volume of the fluid.
48Referencing the newly defined gravitational potential energy, as distance from a body increases, gravitational potential energy tends to:
- AIncrease, approaching zero.
- BDecrease, approaching zero.
- CRemain constant.
- DOscillate depending on the distance.
49Two satellites, A and B, are in circular orbits around Earth. Satellite A orbits closer to Earth than Satellite B. Which has more KE?
- ASatellite A has more KE.
- BSatellite B has more KE.
- CBoth satellites have the same KE.
- DThere is not enough information to determine.
50What is the approximate gravitational acceleration due to Earth at the altitude of the International Space Station (ISS), which orbits at an altitude of about 420 km above Earth's surface?
- A9.8m/s^2
- B8.7m/s^2
- C7.5m/s ^2
- D6.0m/s^2
51Satellite 1 is in a certain circular orbit while orbit while satellite 2 is in a larger circular orbit. Which has the longer orbit?
- ASatellite 1
- BSatellite 2
- CBoth have the same orbit length
- DThere is not enough information to determine
52True or False) If two vectors are exactly opposite in direction, their vector product must be zero.
- AVerdadero
- BFalso
53(True or False) The magnitude of the vector product of two vectors is at a minimum when the vectors are perpendicular.
- AVerdadero
- BFalso
54(True or False) Knowing the magnitude of the vector product of two nonzero vectors and the vectors’ individual magnitudes uniquely determines the angle between them.
- AVerdadero
- BFalso
55Consider two nonzero vectors A and B. Their vector product has the greatest magnitude if A and B are
- AParallel
- BPerpendicular
- CAntiparallel
- DAt a 45 angle
56What is the angle between a force vector F and a torque vector τ generated by F?
- A0°
- B45°
- C90°
- D180°
57A point particle of mass m moves with a constant speed
v along a straight line that passes through point P. What can you say about the angular momentum of the particle relative to point P?- AThe angular momentum is zero.
- BThe angular momentum is constant.
- CThe angular momentum is increasing.
- DThe angular momentum is decreasing.
58A particle travels in a circular path, and point P is at the center of the circle. If the particle’s linear momentum 𝑝 is doubled without changing the radius of the circle, how is the magnitude of its angular momentum about P affected?
- AThe magnitude of the angular momentum is halved.
- BThe magnitude of the angular momentum remains unchanged.
- CThe magnitude of the angular momentum is doubled.
- DThe magnitude of the angular momentum is quadrupled.
59A particle travels in a circular path, and point P is at the center of the circle. If the radius of the circle is doubled but the speed of the particle is unchanged, how is the magnitude of its angular momentum about P affected?
- AThe magnitude of the angular momentum is halved.
- BThe magnitude of the angular momentum remains unchanged.
- CThe magnitude of the angular momentum is doubled.
- DThe magnitude of the angular momentum is quadrupled.
60A particle moves along a straight line at constant speed. How does the particle's angular momentum about any fixed point vary with time?
- AThe angular momentum increases with time.
- BThe angular momentum decreases with time.
- CThe angular momentum remains constant over time.
- DThe angular momentum fluctuates randomly.
61(True or False) If the net torque on a rotating object is zero, the angular velocity of the object cannot change.
- AVerdadero
- BFalso
62If the angular momentum of a system about a fixed point P is constant, which one of the following statements must be true?
- AThe net external force on the system is zero.
- BThe net external torque on the system is zero.
- CThe system is in equilibrium.
- DThe angular velocity of the system is zero.
63Why does a helicopter with just one main rotor have a second smaller rotor mounted on a horizontal axis at the rear?
- ATo provide additional lift
- BTo counteract the torque produced by the main rotor
- CTo increase the forward speed of the helicopter
- DTo stabilize the helicopter in windy conditions
64How does a car's flywheel behave like a spinning top?
- ABoth resist changes in rotational motion due to their inertia
- BBoth lose energy and slow down at the same rate over time
- CBoth use gravitational forces to maintain their motion.
- DBoth are affected by the Coriolis force in a rotating system.
Información
- Descripción
- Test sobre Sin título, creado por Megan Hofmeister el 02/12/2024.
- Autor
- Megan Hofmeister
- Idioma
- English
- Visitas
- 1
- Valoración
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