The first volume (multiple choice questions ***40 points)
First, multiple choice questions
1.(20 10) The following statement about particles is correct ()
A. When studying and observing the solar eclipse, we can regard the sun as a particle.
B. when studying the revolution of the earth, we can regard the earth as a particle.
C. when studying the earth's rotation, we can regard the earth as a particle.
D the nucleus is so small that it must be regarded as a particle.
Answer: b
2. (Last semester of Senior One in Huiyang, Guangdong Province in 2008-09) On the evening of September 25th, 2008, at 2 1: 00, China successfully sent the Shenzhou VII spacecraft developed by China into space, and the spacecraft circled the earth for 90 minutes.
A "2 1: 00 10" and "90 minutes" mean time and time.
B the satellite orbits the earth once with zero displacement and distance.
C the average speed of a satellite orbiting the earth is zero, but its instantaneous speed is not zero all the time.
D the ground satellite control center can treat the spacecraft as a particle when adjusting its flight attitude.
Answer: AC
3. Taking object B as the frame of reference, object A is static, and taking object C as the frame of reference, object A is moving. Then, taking object B as the frame of reference, the motion of object C is ().
A.it must be still
B. it is possible to move or stay still.
C.it must be sporty.
D. insufficient conditions to judge
Answer: c
Analysis: A is stationary with B as the frame of reference, which means that the movements of A and B are exactly the same. Judging the movement of C with B as the frame of reference is the same as judging the movement of C with A as the frame of reference, so the C option is correct.
4. (09- 10 last semester in Xiamen No.1 Middle School, Fujian) Two people started from point A of the circular track at the same speed and walked along ABC and ADC respectively, as shown in the figure. When they meet, the different physical quantities are ().
A. Speed B. Displacement
C. Distance D. Speed
A: A.
5. (Last semester of Senior One in Weifang, Shandong Province, September 2008) Two particles A and B move linearly from the same place in the same direction at the same time, and their V-T images are as shown in the figure, so the following statement is correct ().
A. particle b is at rest and the initial velocity of particle a is zero.
B. the moving speed and direction of particle b remain unchanged.
At the end of 2s, particle A and particle B have the same speed.
At the end of D.2s, particle A and particle B meet.
Answer: BC
Analysis: particle b moves at a uniform speed, and a accelerates, and the initial velocity is zero, so a is wrong and b is right; At the end of the second second, particles A and B have the same speed, but B is in front of A, so C and D are wrong.
6. Someone climbed the mountain, climbed from the foot of the mountain to the top, and then returned to the foot of the mountain by the original road. The average speed of going up the mountain is v 1, and the average speed of going down the mountain is v2, so the size and average speed of going back and forth are ().
A.v 1+v22，v 1+v22
B.v 1-v22，v 1-v22
C.0，v 1-v2v 1+v2
D.0，2v 1v2v 1+v2
Answer: d
Analysis: The displacement is zero, so the average velocity is zero. Let the distance be 2s and the average speed be v = 2sv1+sv2 = 2v1v2v1+v2.
7. (Yinchuan No.1 Middle School 09- 10 Senior One last semester) The following statement about object movement is correct ()
A. If the speed of an object is not zero, its acceleration must also be non-zero.
When an object has acceleration, its speed may be constant.
C. when the acceleration of an object increases, the speed must also increase.
D when the acceleration direction of an object changes, the velocity direction can remain unchanged.
Answer: d
8. (Jiangxi Gao 'an No.2 Middle School 08-09 Senior One last semester) The following table shows the speed changes of four kinds of vehicles, and the following statement is correct ().
Initial speed (m/s), elapsed time (s) and final speed (m/s)
① 2 3 1 1
② 0 3 6
③ 0 20 6
④ 0 100 20
A.① The speed changes the most and the acceleration is the largest.
B.② The speed changes the slowest.
C.③ The speed changes the fastest.
D.④ The terminal speed is the largest, but the acceleration is the smallest.
Answer: d
Analysis: ① It has the fastest speed change, that is, the largest acceleration, and ④ it has the smallest acceleration.
9. 100 meter final (pictured), two timekeepers, A and B, recorded the first place at the same time. When A sees the smoke from the starting gun, B starts to time when he hears the starting gun. When the athletes reach the finish line, A and B stop timing at the same time. It is known that the propagation speed of light in air is about 3.0× 108m/s, and the propagation speed of sound in air is 340 m.
A. Timekeepers A and B recorded the same time.
B. Timekeeper A recorded about 0.3 seconds less time than Timekeeper B.
Timekeeper A recorded about 0.3 seconds more time than timekeeper B.
D. Timekeeper A recorded the time incorrectly.
Answer: c
Analysis: When the sound reaches the timer, the time it takes is: Δ t = XV =100340s ≈ 0.3s. Because of the great speed of light, the time of light in this displacement can be ignored.
10. (Guangdong Zhixin Middle School, Grade One, last semester in 2008-09) The ship went upstream at a constant speed, and when passing under the bridge, the box fell into the water. It was discovered after the ship continued to move forward for a period of time. It immediately turned around and drove downstream at the same still water speed, and caught up with the bridge 7.2km downstream after1h. Then the river speed is ().
A. 7.2 km/h
B. 3.6 km/h
C. 1 m/s
D. The conditions are not enough to determine
Answer: b
Analysis: If the flowing water is taken as the frame of reference, it will take 2 hours for the box to fall into the water and be overtaken by the ship. ∴v water = XT = 7.22 km/h = 3.6 km/h. 。
Volume 2 (60 points for non-multiple choice questions * *)
Fill in the blanks (***4 small questions, each with 6 points and ***24 points. Fill in the answer directly on the horizontal line)
1 1. At present, there are _ _ _ _ _ _ and _ _ _ _ _ timers used in the laboratory. Both of them are connected by alternating current with frequency of 50Hz, so they all hit a dot every _ _ _ _ _ _ _. But the AC voltage of the former is _ _.
Answer: electromagnetic dots; Electric spark; 0.02; 4~6; 220
12. "Dayang-1" is equipped with sonar detection system, which can be used to measure the depth of seawater. The principle is that the ultrasonic generator emits ultrasonic waves vertically to the seabed, and the ultrasonic waves will be reflected back at the seabed. If the wave velocity of ultrasonic waves in seawater is known, the wave velocity of ultrasonic waves in seawater is 1500m/s by measuring the time from transmitting ultrasonic waves to receiving reflected waves. When the ship is stationary, the time from transmitting ultrasonic waves to receiving reflected waves is 8s, so the seawater depth of the ship is _ _ _ _ _ _ _ _ m. 。
Answer: 6000
13. (Last semester of Grade One in Weifang, Shandong, 2008-09) As shown in the figure, a classmate pulls a paper tape by hand and punches holes with an electromagnetic dot timer. A millimeter scale is attached next to the paper tape, and the electromagnetic point timer hits a point every 0.02s s. According to the arrangement of points on the paper tape, it can be judged how the moving speed of the hand changes when the paper tape is pulled by hand. The average speed of hand moving from point A to point C is _ _ _ _ _ m/s, and the speed of hand-pulling paper tape when hitting point C is about _ _ _ _ _ _ _ m/s. 。
Answer: first increase and then decrease by 0. 18m/s 0.39m/s(0.40m/s is also correct).
14. (Zhejiang Xiaoshan No.3 School 09- 10 school year) The speed limit of Shanghai's elevated roads is generally 80 km/h. In order to monitor whether the vehicles are speeding, some "electronic police" systems are set up. The working principle is as shown in the figure: two induction coils A and B are buried at an interval of L under the road surface. When the vehicle passes directly above the coil, the sensor can send it to the data collector. If a car (which can be regarded as a particle in this question) passes through the road at a uniform speed, two sensors send signals to the data collector at a time interval of Δ t, and the speed of the car is obtained after being processed by a microcomputer. If the speed limit is exceeded, the computer will instruct the camera C erected above the road to take pictures of the car, leaving evidence of violation. According to the above information, answer the following questions:
(1) Try to write the expression V = _ _ _ _ _ _ _ for calculating the speed of a car by a microcomputer.
(2) If L = 5m and Δ δt = 0.3s, the camera works _ _ _ _ _ _ _ (fill in "Yes" or "No").
Answer: (1) L δ T (2) No.
Third, discuss the calculation problem (this is entitled ***4 small questions, with a score of ***36. The answer should be written with necessary words, equations and important calculation steps. Only the final answer can't be scored, and there is numerical calculation. The values and units in the answer must be clearly written.)
15.(8 points) As shown in the figure, a car was driving on a straight road at a speed of 72km/h, and the driver suddenly found a deer on the road ahead, so he immediately braked and the car stopped within 4 seconds to prevent the deer from being hurt. Try to find the average acceleration in the process of automobile braking.
Answer: -5m/s2
Analysis: In the process of braking, the initial speed of the car is V 0 = 72 km/h = 20 m/s, the final speed is V 0, and the movement time is T = 4 s. According to the definition of acceleration, the acceleration during braking is calculated.
a=v-v0t=0-204m/s2=-5m/s2。
The negative sign in the formula indicates that the vehicle speed is decreasing, that is, the vehicle speed decreases by 5m/s per second on average after braking.
16.(8 points) Xiao Li told a story about a race between a tortoise and a rabbit. According to the story told by Xiao Li, the displacement images of rabbits and turtles are shown in the picture. Please tell the story according to the coordinates and physical terms in the image. Please answer the following questions before you tell the story.
(1) Did the rabbit and tortoise in Xiao Li's story set off at the same time and place?
(2) What sports does the tortoise do?
(3) How many times did the rabbit and the tortoise meet in the competition?
(4) Which one arrives at the destination first by the predetermined displacement xm?
Answer: (1) Starting from the same place but not at the same time.
(2) Uniform linear motion.
(3) Assemble at 3)t2 and t4 respectively.
(4) The tortoise reached the finish line first.
17.( 10) (Chengdu Aerospace Middle School 09- 10, the first semester of the school year) A car starts from the origin O and moves in a straight line along the X axis.
In order to study the movement of a car, write down its position and speed at any time. Please refer to the following table:
Time t/s 0 1 234 567
Location coordinates x/m00.524.58121620.
Instantaneous velocity v/(m? s- 1) 1 2 3 4 4 4 4
(1) What is the instantaneous speed of the car at the end of the second second?
(2) What is the acceleration of the car in the first 3 seconds?
(3) What is the average speed of the car in the 4th second?
Answer: (1) 3m/s (2)1m/S2 (3) 3.5m/s.
Analysis: (1) v2 = 3m/s
(2)a =δvδt = 4-23- 1m/S2 = 1m/S2
(3)δx4 = 3.5m，t= 1s，v4 =δx4t 4 = 3.5m/s。
18.( 10 minutes) A bus is driving on the expressway. When passing through a straight section, the driver drives in a straight line at a constant speed. The driver found that the front was about to pass through the tunnel under the mountain cliff, so he honked his horn and heard an echo five seconds later. After hearing the echo, the driver honked the horn for the second time at 10s, and heard the echo after 3s. Please help the driver calculate the speed of the bus according to the above data to see if the bus is speeding and remind the driver to drive safely. It is known that the maximum speed limit of this expressway is 1 10km/h (as shown in the figure), and the sound propagation speed in the air is 340 m/s. 。
Answer: 87.5km/h, no speeding.
Analysis: Let the speed of the bus be v 1, the speed of sound be v2, and the distance from the bus to the cliff is l when the bus whistles for the first time. From the meaning of the question, there should be 2L-V 1× 5 = V2× 5 in the process from the first whistle to the echo. When the bus horns for the second time, the distance from the bus to the cliff is L' = L-V 1× 15, and in the same way, it is 2L'-V 1× 3 = V2× 3, that is, 2 (L-V/kloc-0 /×/kloc-0.