Source: Published on April 2, 2007.
Physics mid-term examination paper of the second day of junior high school
(Total score: 100; Completion time: 90 minutes)
I. Fill in the blanks (32 points)
1, all objects, always keep the sum. This is Newton's first law.
2. As shown in the figure, the car with the weight of 100 N moves in a straight line at a uniform speed on a smooth horizontal plane, so the thrust on the car in the horizontal direction is. Please draw a schematic diagram of the force on the car in the picture.
3. Weightlifters lift the barbell of 1.600 cattle over their heads with the strength of 2000 cattle. At this time, the resultant force on the barbell is the direction of resultant force.
4. A car with a mass of 10 ton is moving in a straight line at a constant speed. If the resistance it receives is 0.02 times the weight of the car, then the traction of the car is cattle, and the ground support of the car is cattle.
In the 100 meter race, when the athletes reach the finish line, they can't stop immediately. This is because athletes should keep in shape and move on.
6. For the same indoor floor, it is better to push heavy furniture than light furniture. This is because the pressure of heavy furniture on the ground is greater than that of light furniture, and the friction between heavy furniture and the ground is greater.
7. When a person with a mass of 50㎏ stands, the ground pressure is 3× 104 Pa, and when walking, the ground pressure is Pa.
8. The air pressure values measured by mountaineers at different heights A and B are 8.5× 104 Pa and 7.8× 104 Pa respectively, so the height at A is higher than that at B, and the boiling point of water at A is higher than that at B .. (Write "high" or "low" on it).
9. When the submarine bears the water pressure of 1.96× 105 Pa underwater, its depth is Pa. If it dives to 10 meter, it is Pa. If you go horizontally 10 meter, it is Pa.
The standard atmospheric pressure of 10 and 1 is equivalent to the pressure generated by a one-centimeter-high mercury column, which is equal to Pa.
1 1. On the horizontal plane, when a brick is placed vertically, the ground pressure is F 1, and when it is placed laterally, it is f1f2p1P2 (fill in ">").
12, an object weighing 50 newtons is suspended under the balloon and rises at a constant speed. The resultant force on an object is a cow. When the cable suddenly breaks, the object will move in that direction. If the air resistance on an object is calculated, the force on the object at this time is the cow and the direction.
13 As shown in the figure, container A and container B have exactly the same shape and volume, and they are filled with the same liquid, so the pressure of the two containers on the horizontal plane is F A F B, and the pressure of the two containers on the horizontal plane is P A P B；; Liquid pressure at the bottom of the container P'A P'B Liquid pressure at the bottom of the container F'A F'B (fill in ">")
Second, multiple-choice questions (20 points)
1, the textbook still on the horizontal desktop, the balance force is ()
A, the gravity of the textbook and its pressure on the desktop B, the pressure of the textbook on the desktop and the support of the desktop on the textbook.
C, the gravity of the textbook and the support of the desktop for it D, all of the above.
2, an object under the action of two forces, the three elements of the two forces are exactly the same, then the two forces ()
A, it must be a balancing force B, and it must not be a balancing force.
C, maybe the balance force d, can't be sure.
3. If an object can be pulled up at a uniform speed in the vertical direction with a force of 600 N, then the force required to put it down at a uniform speed in a solid and straight direction (excluding air resistance) is ().
A, if it is less than 600 N, apply force upwards; B, if it is equal to 600 N, apply force downward.
C, less than 600 N, apply downward force D, which is equal to 600 N, and apply upward force.
Due to the balance force, the object moves in a straight line at a uniform speed. When the force acting on the object disappears at the same time, the object ().
A, in a static state B, in a state of uniform linear motion
C, can do uniform linear motion D, all of the above are possible.
5, about pressure, air pressure, the following statement is correct ()
First, the pressure is always equal to the gravity of the object in numerical value.
The direction of pressure is always vertical downward.
C, when the stress area is fixed, the greater the pressure, the greater the bearing surface pressure.
D, the smaller the pressure of the object on the bearing surface, the smaller the pressure.
6, the following belongs to the atmospheric pressure application phenomenon is ()
A, pinch the ball hard, the ball becomes flat. B, the basketball bounced back after hitting the rebound.
C, leave a small hole d on the teapot cover, and inject the liquid medicine into the muscle.
7. As shown in the figure, there are two identical cylindrical containers on the horizontal desktop, which are respectively filled with liquid A and liquid B with the same mass. As we all know, P A < P B, then pressure and pressure ()
A，F A =F B P A < P B，F A < F B P A < P B。
c，F A =F B P A =P B D，F A < F B P A =P B。
8, in the following example, increase the pressure is ()
A. Laying sleepers under the tracks of the railway; B, install the crawler on the tank wheel.
C, the foundation of the building is wide. D, knives and axes sharpen.
9. A classmate was walking on the frozen lake when he suddenly found that the ice under his feet was about to crack. The measure he should take is ().
A, run to the shore quickly. Stand still
C. Crawl on the ice and slowly move to the shore. D, immediately change to stand on one foot.
10, the bottom area ratio of the three containers is 3: 2: 1, and the containers contain the same liquid. If the pressure of the liquid at the bottom of the container is equal, the ratio of the depth of the liquid in the container is ().
a、 1:2:3 B、3:2: 1 C、 1:3:6 D、2:3:6
Three, short answer questions (8 points)
1. What happens when a runner's foot hits an obstacle? Why?
Please find four examples of using atmospheric pressure to serve us in our daily life.
Four, experimental questions (23 points)
1, studying "which factors are related to the magnitude of sliding friction:
(1) Use a spring scale to pull the wooden block to move on the placed long board.
(2) According to the conditions, we can know the pulling force and friction force of the wood block in the horizontal direction.
(3) The experiment shows that the magnitude of friction is similar to that of friction.
2. When studying the internal pressure of liquid:
(1) Besides using beaker, water and salt water, it is also necessary to measure the depth of metal box in water.
(2) When measuring, if the metal box is kept 5㎝ below the water surface and the orientation of the rubber film is changed, we can see the height difference between the two tubes of the U-shaped tube, indicating that the liquid exists in all directions with the same and equal depth.
3. In "Torricelli Experiment"
(1) The purpose of filling the glass tube with mercury is to discharge the tube, so that when the tube is inverted and inserted into the mercury tank, mercury in the tube may be formed.
(2) Under the standard atmospheric pressure, the glass tube is lifted by 65438±0cm, and the height difference between the inside and outside of the tube is cm; If the glass tube is slightly inclined, the height difference between the inside and outside of the tube is cm. If a small hole is opened at the top of the test tube at this time, the mercury in the test tube will be reduced. If a glass tube with a diameter of 1㎝ is used first and then a glass tube with a diameter of 2㎝, the height difference between the inside and outside of the tube is cm.
4. Heat the water in the flask with an alcohol lamp. When the water is boiling, take off the alcohol lamp and the water in the flask will stop. When the water temperature is slightly lower, connect the pump to the bottle mouth and pump air outward, so that the air pressure in the flask can observe the water in the flask at this time, indicating that the boiling point of water is at atmospheric pressure.
V. Calculation problem (17, below g= 10 N/kg)
1. An object is acted by two forces F 1 and F2 on the same line, where F 1=30 N and F2 = 40 N. What is the resultant force of these two forces? What is the direction? (4 points)
2. A cubic iron block with a side length of 8 cm is placed on a horizontal desktop with an area of 100 cm2. What is the pressure on the desktop? (5 points) (ρ iron = 7.9× 103kg/m3)
3. As shown in the figure, there is a container weighing 10N on the horizontal desktop, which is just filled with 14Kg of water, and the bottom area of the container is 500 cm2. In the figure, h1= 20cm, H2 = 5cm. Find: (1) pressure at the bottom of the container and pressure (2). (8 points)
There are many physics test questions in word format for senior two students.
[Physics Test of Senior Two] Anonymous Physical Optics Test of Senior Two 09-28
[Physics Test of Senior Two] Shimen Experimental Middle School participated in the physics test of Senior Two anonymously in the last semester of 2008.
[Physics Test of Senior Two] Physics Test of Senior Two in Huazhou No.3 Middle School in 2008, anonymous 09-28.
[Physics Test in Senior Two] The physics test in the second semester of Senior Two is anonymous 09-28.
[Physics Test Paper for Senior Two] Physics Mid-term Test Paper for Senior Two
/englishsoft/List_49.html
References:
/englishsoft/List_49.html
3. As shown in the figure, there is a container weighing 10N on the horizontal desktop, which is just filled with 14Kg of water, and the bottom area of the container is 500 cm2. In the figure, h1= 20cm, H2 = 5cm. Find: (1) pressure at the bottom of the container and pressure (2). (8 points)
There are many physics test questions in word format for senior two students.
[Physics Test of Senior Two] Anonymous Physical Optics Test of Senior Two 09-28
[Physics Test of Senior Two] Shimen Experimental Middle School participated in the physics test of Senior Two anonymously in the last semester of 2008.
[Physics Test of Senior Two] Physics Test of Senior Two in Huazhou No.3 Middle School in 2008, anonymous 09-28.
[Physics Test in Senior Two] The physics test in the second semester of Senior Two is anonymous 09-28.
[Physics Test Paper for Senior Two] Physics Mid-term Test Paper for Senior Two
/englishsoft/List_49.html
References:
/englishsoft/List_49.html