MOOC 普通物理Ⅰ(大连理工大学)1001956002 最新慕课完整章节测试答案

Test 10 (for DUT-UCI JP )

1、单选题：
‏A meter stick is supported by a knife-edge at the 50-cm mark. Doug hangs masses of 0.40 and 0.60 kg from the 20-cm and 80-cm marks, respectively. Where should Doug hang a third mass of 0.30 kg to keep the stick balanced?‍
选项：
A: 20 cm
B: 70 cm
C: 30 cm
D: 25 cm
E: 15 cm
F: 85 cm
G: 10 cm
答案: 【 30 cm】

2、单选题：
‍An 800-N billboard worker stands on a 4.0-m scaffold supported by vertical ropes at each end. If the scaffold weighs 500 N and the worker stands 1.0 m from one end, what is the tension in the rope nearest the worker?​
选项：
A: 450 N
B: 500 N
C: 800 N
D: 850 N
E: 950 N
F: 1050 N
G: 350 N
答案: 【 850 N】

3、单选题：
‍An 800-N billboard worker stands on a 4.0-m scaffold weighing 500 N and supported by vertical ropes at each end. How far would the worker stand from one of the supporting ropes to produce a tension of 550 N in that rope?‏
选项：
A: 1.4 m
B: 2.0 m
C: 2.5 m
D: 2.7 m
E: 3.7 m
F: 1.7 m
答案: 【 2.5 m】

4、单选题：
‏A uniform, horizontal beam of length 6.0 m and weight 120 N is attached at one end to a wall by a pin connection (so that it may rotate). A cable attached to the wall above the pin supports the opposite end. The cable makes an angle of 60° with the horizontal. What is the tension in the cable needed to maintain the beam in equilibrium?‏
选项：
A: 35 N
B: 69 N
C: 60 N
D: 120 N
E: 110 N
F: 100 N
答案: 【 69 N】

5、单选题：
‌A uniform 1.0-N meter stick is suspended horizontally by vertical strings attached at each end. A 2.0-N weight is suspended from the 10-cm position on the stick, another 2.0-N weight is suspended from the 50 cm position, and a 3.0-N weight is suspended from the 60 cm position. What is the tension in the string attached at the 100-cm end of the stick?‏
选项：
A: 1.9 N
B: 3.0 N
C: 3.5 N
D: 4.0 N
E: 4.5 N
F: 4.9 N
答案: 【 3.5 N】

6、单选题：
‏An object of mass 0.50 kg is transported to the surface of Planet X where the object's weight is measured to be 20 N. The radius of the planet is 4.0 ×10^6 m. What is the mass of Planet X? (G = 6.67 ×10^-11 N × m^2/kg^2)‏
选项：
A: 13 ×10^19 kg
B: 17 ×10^22 kg
C: 9.6 ×10^24 kg
D: 21 ×10^25 kg
E: 22 ×10^29 kg
F: 21 ×10^28 kg
答案: 【 9.6 ×10^24 kg】

7、单选题：
‎An object of mass 0.50 kg is transported to the surface of Planet X where the object's weight is measured to be 20 N. The radius of the planet is 4.0 ×10^6 m. What free fall acceleration will the 0.50-kg object experience when transported to a distance of 2.0 × 10^6 m from the surface of this planet?‎
选项：
A: 90 m/s^2
B: 20 m/s^2
C: 13 m/s^2
D: 18 m/s^2
E: 28 m/s^2
F: 38 m/s^2
答案: 【 18 m/s^2】

8、单选题：
‎An asteroid has a perihelion (the orbit's closest approach to the sun) of 1.5 AU and a period of revolution of 8.0 y. What is its greatest distance from the sun (its aphelion)?‌
选项：
A: 8.0 AU
B: 6.5 AU
C: 4.0 AU
D: 2.5 AU
E: 3.5 AU
F: 4.5 AU
G: 5.5 AU
答案: 【 6.5 AU】

9、单选题：
​Two satellites are monitored as they orbit the Earth; satellite X is eight times as far from the Earth's center as is satellite Y. From Kepler's third law one may conclude that the period or revolution of X is what factor times that of Y?​
选项：
A: 1/2
B: 2.0
C: 4.0
D: 22.6
E: 12.6
F: 2.7
答案: 【 22.6】

10、单选题：
​An artificial Earth satellite in an elliptical orbit has its greatest centripetal acceleration when it is at what location?​
选项：
A: nearest the Earth
B: farthest from the Earth
C: between Earth and Moon
D: between Earth and Sun
E: none of the others
答案: 【 nearest the Earth】

Test 9 (for DUT-UCI JP )

1、单选题：
‎A rod of length L is pivoted about its left end and has a force F applied perpendicular to the other end. The force F is now removed and another force F' is applied at the midpoint of the rod. If F' is at an angle of 30° with respect to the rod, what is its magnitude if the resulting torque is the same as when F was applied?​
选项：
A: F
B: 2F
C: 3F
D: 4F
E: 5F
F: 6F
G: 7F
答案: 【 4F】

2、单选题：
‎A bucket of water with total mass 23 kg is attached to a rope, which in turn, is wound around a 0.050-m radius cylinder at the top of a well. A crank with a turning radius of 0.25 m is attached to the end of the cylinder. What minimum force directed perpendicular to the crank handle is required to just raise the bucket? (Assume the rope's mass is negligible, that cylinder turns on frictionless bearings, and that g = 9.8 m/s^2.)​
选项：
A: 45 N
B: 68 N
C: 90 N
D: 135 N
E: 35 N
F: 15 N
答案: 【 45 N】

3、单选题：
‍A baseball pitcher loosens up his pitching arm. He tosses a 0.15-kg ball using only the rotation of his forearm, 0.32 m in length, to accelerate the ball. If the ball starts at rest and is released with a speed of 12 m/s in a time of 0.40 s, what torque is applied to the ball while being held by the pitcher's hand to produce the angular acceleration?‏
选项：
A: 1.1 N∙m
B: 11 N∙m
C: 7.2 N∙m
D: 1.4 N∙m
E: 14 N∙m
F: 3.4 N∙m
答案: 【 1.4 N∙m】

4、单选题：
​A bucket of water with total mass 23 kg is attached to a rope, which in turn is wound around a 0.050-m radius cylinder at the top of a well. A crank with a turning radius of 0.25 m is attached to the end of the cylinder and the moment of inertia of cylinder and crank is 0.12 kg∙m^2. If the bucket is raised to the top of the well and released, what is the acceleration of the bucket as it falls toward the bottom of the well? _______m/s^2. (Assume rope's mass is negligible, that cylinder turns on frictionless bearings and that g = 9.8 m/s^2.)‍
选项：
A: 3.2 
B: 6.3 
C: 7.4 
D: 9.8 
E: 98 
F: 12.5
G: 19.8 
答案: 【 3.2 】

5、单选题：
​A ventilation fan with a moment of inertia of 0.034 kg∙m^2 has a net torque of 0.11 N∙m applied to it. If it starts from rest, what kinetic energy will it have 8.0 s later?‌
选项：
A: 31 J
B: 17 J
C: 11 J
D: 6.6 J
E: 8.6 J
F: 3.6 J
答案: 【 11 J】

6、单选题：
‏A solid sphere of mass 4.0 kg and radius 0.12 m starts from rest at the top of a ramp inclined 15°, and rolls to the bottom. The upper end of the ramp is 1.2 m higher than the lower end. What is the linear speed of the sphere when it reaches the bottom of the ramp? (Note: I = 0.4MR^2 for a solid sphere and g = 9.8 m/s^2)​
选项：
A: 4.7 m/s
B: 4.1 m/s
C: 3.4 m/s
D: 2.4 m/s
E: 1.4 m/s
F: 3.1 m/s
答案: 【 4.1 m/s】

7、单选题：
‌A figure skater on ice with arms extended, spins at a rate of 2.5 rev/s. After he draws his arms in, he spins at 6.0 rev/s. By what factor does the skater's kinetic energy change when he draws his arms in?‏
选项：
A: 2.4
B: 1.0
C: 0.42
D: 0.12
E: 0.012
F: 0.18
答案: 【 2.4】

8、单选题：
​A turntable has a moment of inertia of 3.0×10^-2 kg∙m2 and spins freely on a frictionless bearing at 25 rev/min. A 0.30-kg ball of putty is dropped vertically on the turntable and sticks at a point 0.10 m from the center. By what factor does the kinetic energy of the system change after the putty is dropped onto the turntable?‏
选项：
A: 0.91
B: 1.0
C: 0.82
D: 1.5
E: 2.5
F: 11.5
G: 3.5
答案: 【 0.91】

9、单选题：
​Two equal magnitude forces are in opposite directions and their lines of action are separated by distance d. These two forces are applied to a solid disk, which is mounted on a frictionless axle. If d is half the radius r of the disk, which of the following positions for the forces would give the most torque.​
选项：
A: One force on a line touching the circumference of the disk, the other on a line halfway to the center.
B: One force on a line at a distance d from the center and the other on a line through the center of the disk.
C: One force on a line at a distance d/2 from the center of the disk, and the other on a line at a distance d/2 on the opposite side of the center of the disk.
D: Since all the other orientations give the same torque, choose this answer.
答案: 【 Since all the other orientations give the same torque, choose this answer.】

10、单选题：
‍A uniform meter stick balances on a fulcrum placed at the 40 cm mark when a weight W is placed at the 30 cm mark. What is the weight of the meter stick?‌
选项：
A: W
B: 2W
C: W/2
D: 0.4 W
E: 4 W
F: 5 W
答案: 【 W】

Test3( for international class)

1、单选题：
‍A grindstone increases in angular speed from 4.00 rad/s to 12.00 rad/s in 4.00 s. Through what angle does it turn during that time interval if the angular acceleration is constant?‏
选项：
A: 8.00 rad
B: 12.0 rad
C: 16.0 rad
D: 32.0 rad
答案: 【 32.0 rad】

2、单选题：
Consider an object on a rotating disk a distance r from its center, held in place on the disk by static friction. Which of the following statements is not true concerning this object?‌‏‌
选项：
A: If the angular speed is constant, the object must have constant tangential speed.
B: If the angular speed is constant, the object is not accelerated.
C: The object has a tangential acceleration only if the disk has an angular acceleration.
D:  If the disk has an angular acceleration, the object has both a centripetal acceleration and a tangential acceleration.
E: The object always has a centripetal acceleration except when the angular speed is zero
答案: 【 If the angular speed is constant, the object is not accelerated.】

3、单选题：
​A solid aluminum sphere of radius R has moment of inertia I about an axis through its center. Will the moment of inertia about a central axis of a solid aluminum sphere of radius 2R be‍
选项：
A: 2I
B: 4I
C:  8I
D: 32I
答案: 【 32I】

4、单选题：
An ice skater starts a spin with her arms stretched out to the sides. She balances on the tip of one skate to turn without friction. She then pulls her arms in so that her moment of inertia decreases by a factor of 2. In the process of her doing so, what happens to her kinetic energy?‏​‏
选项：
A:  It increases by a factor of 4.
B: It increases by a factor of 2.
C:  It decreases by a factor of 2.
D:  It decreases by a factor of 4.
答案: 【 It increases by a factor of 2.】

5、单选题：
Consider an isolated system moving through empty space. The system consists of objects that interact with each other and can change location with respect to one another. Which of the following quantities can change in time?‏‏‏
选项：
A: The angular momentum of the system.
B: The linear momentum of the system.
C: Both the angular momentum and linear momentum of the system.
D: Neither the angular momentum nor linear momentum of the system.
答案: 【 Neither the angular momentum nor linear momentum of the system.】

6、单选题：
 Two ponies of equal mass are initially at diametrically opposite points on the rim of a large horizontal turntable that is turning freely on a frictionless, vertical axle through its center. The ponies simultaneously start walking toward each other across the turntable.、 As they walk, what happens to the angular speed of the turntable?‎​‎
选项：
A:  It increases.
B:  It decreases.
C:  It stays constant.
D: Not Sure
答案: 【  It increases.】

7、单选题：
‎A turntable rotates with a constant 2.25 rad/s^2 angular acceleration. After 4.00 s it has rotated through an angle of 60.0 rad. The angular velocity of the wheel at the beginning of the 4.00s interval was‌
选项：
A:  10.5 rad/s
B:  19.5 rad/s
C:  14.5 rad/s
D:  17.5 rad/s
答案: 【  10.5 rad/s】

8、单选题：
A solid, uniform cylinder with mass 8.25 kg and diameter 15.0 cm is spinning at 220 rpm on a thin, frictionless axle that passes along the cylinder axis. You design a simple friction brake to stop the cylinder by pressing the brake against the outer rim with a normal force. The coefficient of kinetic friction between the brake and rim is 0.333. What must the applied normal force he to bring the cylinder to rest after it has turned through 5.25 revolutions?‍‏‍
选项：
A: 14.9N
B: 2.49N
C: 7.47N
D: 5.47N
答案: 【 7.47N】

9、单选题：
Two particles of different mass start from rest. The same net force acts on both of them as they move over equal distances. How do their final kinetic energies compare?​‎​
选项：
A: The particle of larger mass has more kinetic energy.
B: The particle of smaller mass has more kinetic energy.
C: The particles have equal kinetic energies.
D:  Either particle might have more kinetic energy.
答案: 【 The particles have equal kinetic energies.】

10、多选题：
A constant net torque is exerted on an object. Which of the following quantities for the object cannot be constant? Choose all that apply.‍‍‍
选项：
A: angular position
B: angular velocity
C: angular acceleration
D: moment of inertia
E: kinetic energy
答案: 【 angular position;
angular velocity;
kinetic energy】

Test 5 ( Periodic Motion) (for international students)

1、单选题：
‏‌A mass of 0.20 kg, hung from a spring with a spring constant of 80.0 N/m, is set into an up-and-down simple harmonic motion. If the mass is displaced from equilibrium by 0.10 m and released from rest, what is its speed when moving through the equilibrium point?‏
选项：
A: 0
B: 1.4 m/s
C: 2.0 m/s
D: 3.4 m/s
答案: 【 2.0 m/s】

2、单选题：
‏ A particle on a spring moves back and forth in simple harmonic motion along the x-axis between  x1=100 cm and x2= 140 cm. The position where the particle has its maximum kinetic energy is x0 = ______________  .‏
选项：
A: 100 cm
B: 140 cm
C: 40 cm
D: 120 cm
答案: 【 120 cm】

3、单选题：

​

‍选项：
A:
B:
C:
D:
答案: 【 】

4、单选题：
‏One person swings on a swing and finds that the period is 3.0 s. A second person of equal mass joins him. With two people swinging, the period is __________________  . ​
选项：
A: 不变
B: 变大
C: 变小
D: 无法判断
答案: 【 不变】

5、单选题：

‎

‍选项：
A: 2.4 s
B: 1.2 s
C: 4.8 s
D: 4.0 s
答案: 【 4.8 s】

6、单选题：
‏If the amplitude of a system moving in simple harmonic motion is doubled, which of the following quantities doesn’t change?‌
选项：
A: Total energy.
B: Maximum speed.
C: Maximum acceleration.
D:  Period.
答案: 【  Period.】

7、多选题：
‏A mass m is resting on a horizontal frictionless surface attached to a spring of spring force constant k . At time t = 0 , the mass is given a sharp blow, causing it to move the right with speed v . The next time the mass will have this speed is _________________ .‍
选项：
A:
B:
C:
D:
答案: 【 ;
】

8、判断题：

‏A mass m hanging on a spring oscillates vertically. If the equilibrium point of the oscillation is a distance d below the relaxed length of the spring and if the amplitude of the oscillation is A. The maximum kinetic energy of the oscillation is .

‏选项：
A: 正确
B: 错误
答案: 【 正确】

9、判断题：
‍When a body oscillating on a horizontal spring passes through its equiibrium position, its acceleration is zero. When the bob of an oscillationg simple pendulum passes through its equilibrium position ,is its acceleration zero?‏
选项：
A: 正确
B: 错误
答案: 【 错误】

10、填空题：
‏An airplane is flying in a straight line at a constant altitude. If a wind gust stikes and raises the nose of the airplane, the nose will bob up and down until the airplane eventually returns to its original attitude. Are these oscillations ________________ ( underdamped/critically damped/ overdamped)?‌
答案: 【 underdamped】

Test 6 (Mechanical Waves) (for international students)

1、单选题：

‎

‏选项：
A:
B:
C:
D:
答案: 【 】

2、单选题：
‏A block is attached to a spring hung vertically. After being slowly lowered, it is hung at rest with the spring stretched by 15.0 cm. If the block is raised back up and released from rest with the spring unstretched, what is the amplitude of its oscillations?‌
选项：
A: 7.5 cm
B: 15.0 cm
C: 30.0 cm
D: 60.0 cm
答案: 【 15.0 cm】

3、单选题：

‌

‎选项：
A:
B:
C:
D:
答案: 【 】

4、单选题：

‍

‎选项：
A: maximum; 
B: minimum; 
C: zero; 
D: no choice. 
答案: 【 zero; 】

5、单选题：

​

‎选项：
A: 0.6 m; 
B: 3.0 m; 
C: 75 m;
D: 375 m.
答案: 【 75 m;】

6、单选题：

‎

​选项：
A:
B:
C:
D:
答案: 【 】

7、单选题：

​

‍选项：
A:
B:
C:
D:
答案: 【 】

8、判断题：
‌There is string with both ends fixed. The standing wave was produced on it. Now suppose the frequency of the standing wave were doubled. All of the nodes would increase and new nodes would locate between every pari of old nodes.  Is this right or wrong?‍
选项：
A: 正确
B: 错误
答案: 【 正确】

9、填空题：
​A pendulum clock depends on the period of a pendulum to keep correct time. Suppose a pendulum clock is keeping correct time and then you slide the bob of the pendulum downward on the oscillating rod. The clock runs (fill in slow or fast or correctly)               .‎
答案: 【 slow】

10、填空题：
​If a grandfather clock were running slow, to make a correction we should slide the bob (fill in downward or upward)                              .‍
答案: 【 upward】

Test 7 (Sound and Hearing) (for international students)

1、单选题：

‌Figure Problem shows a standing wave on a 2.0 m long string that has been fixed at both ends and tightened until the wave speed is 40 m/s . The frequency is _____________ .

‎

‌

‎选项：
A: 40Hz
B: 80 Hz
C: 160 Hz
D: 20 Hz
答案: 【 40Hz】

2、单选题：
​You are tuning a guitar by comparing the sound of the string with that of a standard tuning fork. You notice a beat frequency of 5 Hz when both sounds are present. As you tighten the guitar string, the beat frequency rises steadily to 8 Hz. To tune the string exactly to the tuning fork, which is what you will do?‏
选项：
A:  Loosen the string. 
B: Continue to tighten the string.
C: Impossible to determine for the given information. 
D: Done nothing.
答案: 【  Loosen the string. 】

3、单选题：

‍

‏

‍

‏

‍

‏

‍

‏选项：
A: 4
B: 8
C: 12
D: 16
答案: 【 8】

4、单选题：

‏

​选项：
A:
B:
C:
D:
答案: 【 】

5、单选题：
​An open pipe of air supports standing waves at frequencies of 300 Hz and 400 Hz. There are no other frequencies between these two. What is the frequency of the second harmonic of this tube? ‏
选项：
A: 100 Hz
B: 200 Hz
C: 400 Hz
D: 600 Hz
答案: 【 200 Hz】

6、多选题：
​When two tuning forks are sounded at the same time, a beat frequency of 5 Hz occurs. If one of the tuning forks has a frequency of 245 Hz, the frequency of the other tuning fork is                          .‍
选项：
A: 260 Hz
B: 250 Hz
C: 240 Hz
D: 235 Hz
答案: 【 250 Hz;
240 Hz】

7、多选题：
‎A stopped organ pipeof length L has a fundamental frequency of 220 Hz. For which of the following organ pipes will there be a resonance if a tuning fork of frequency 660 Hz is sounded next to the pipe?‎
选项：
A:  A stopped organ pipe of length L.
B: A stopped  organ pipe of length 2L.
C:  An open organ pipe of length L. 
D: An open organ pipe of length 2L.
答案: 【  A stopped organ pipe of length L.;
An open organ pipe of length 2L.】

8、判断题：
‎You double the intensity of a sound wave in air while leaving the frequency unchanged. (The pressure, density, and temperature of the air remain unchanged as well.) Then the displaement amplitude, pressure amplitude, sound speed, and sound intensity level, all of these quantities are unchanged. Please judge this statement is correct or incorrect?‌
选项：
A: 正确
B: 错误
答案: 【 错误】

9、填空题：
​Suppose you are riding on a hot air balloon, carrying a buzzer that emits a sound of frequency f . If you accidentally drop the buzzer over the side while the balloon is rising at constant speed, the frequency and intensity of what you can hear sound as the buzzer falls toward the ground  _________