Physics in the car

With the development of the economy and the continuous improvement of people’s living standards, the most important means of transportation in modern life-car, And our lives are getting closer and closer. In frequent contact with it, careful observation and serious thinking, we will find that almost every aspect of the junior high school physics knowledge system is involved in the design and use of cars. Pay attention to experience during the process, there may be more new and unexpected gains! 1. Mechanics 1. The quality of the car's chassis is relatively large, which can lower the center of gravity of the car and increase the stability of the car when driving. 2. The car's body is designed to be streamlined in order to reduce the resistance when the car is running. 3. The driving power of the car-the friction of the ground against the driving wheel (the direction of friction between the driving wheel and the driven wheel and the ground is opposite) 4. When the car is advancing at a constant speed on a straight road-traction and resistance are balanced with each other, and the gravity of the car is balanced with the support of the ground 5. When the car turns: ①The driver has to hitsteering wheel—— Force is the reason for changing the motion state of the object; ②Passengers will fall in the opposite direction of turning——Because the passengers have inertia 6. The car is in a hurrybrake(Deceleration), ① the driver steps on the brakes-force is the reason for changing the motion state of the object; ② the passengers will fall in the direction of the car-inertia; ③ the driver can brake the car with a small amount of force-the principle of lever; ④ Press harder on the brake-increase the pressure to increase the friction; ⑤ When braking suddenly, the friction between the wheels and the ground changes from rolling to sliding friction 7. There are also differences in size and number of wheels for different uses of cars-this is related to the pressure on the road by the car 8. AutomotiveSeatBoth are designed to be wide and large, which reduces the pressure on the rider and makes the ride comfortable 9. When a car is driving fast, a low-pressure zone will be formed at the rear of the car. This is the reason why we can often see the dust from the rear of a moving car. 10. The requirements of the traffic management department: ①The driver and front passenger of the car must be fastenedseat belt——This can prevent the hazard of inertia; ②It is strictly forbidden to overload the vehicle—not only to reduce the damage of the vehicle to the road, but also to reduce friction and inertia; Too long moving distance caused a car accident 11. Application of simple machinery: ①steering wheel, wheels, window cranks, etc. are all axles, ②speed control lever, automaticswitchThe door device is a lever 12. When the car is climbing, it should be adjusted to a low speed: from P=Fv, when the power is constant, reduce the speed to increase the traction 13. Regarding the calculation of speed, distance and time; the description of the reference object and the state of motion 14. Recognize the speed limit, mileage, and no-beep signs, and understand their meanings 2. Acoustics 1,car hornThe sound should be loud, and the sound of the engine should be eliminated as much as possible (the engine is equipped with a silencer)-this is to reduce the noise at the sound source 2. In order to reduce the impact of noise from vehicles on roadside residents, set up barriers or plant trees along the roadside-the noise can be reduced during the propagation process 3. Horn sound: electrical energy-mechanical energy 3. Thermal aspects 1. Diesel or gasoline engines are commonly used in automobile engines-they are internal combustion engines-use internal energy to do work 2. The engine is equipped with a water jacket, which uses circulating water to help the engine dissipate heat-the specific heat capacity of water is large 3. In winter, to prevent frost damageWater tank, Drain the water in the water tank at night-to prevent the hazards of thermal expansion and contraction 4. There are rows of electric heating wires embedded in the rear window glass of the car-it can prevent the fog formed in the car from adhering to the glass and condensing 5. When you just get in a car or when a car passes by you, you will smell a strong smell of gasoline-diffusion phenomenon 6. The window glass of the air-conditioned vehicle is designed to be double-layered to prevent heat transfer 7. Environmentally friendly vehicles use gas fuel, which can reduce air pollution 4. Electricity 1. The engine of a car is usually started by a low-voltage motor: the motor is made according to the principle of the effect of the magnetic field on the current, and converts electrical energy into mechanical energy during operation. 2. Car batteries commonly used in car motors (car motors) (Accumulator) Power supply, the wheels that can be used during the operation of the car drive the carDynamoGenerate electricity and charge the battery.When charging the battery, the electrical energy is converted into chemical energy and stored. At this time, the battery is used as an electrical appliance; when the battery is used to power the motor, the chemical energy is converted into electrical energy, and the battery is the power source at this time. 3. The car battery is also used to supply power for the air conditioner, electric fan, radio cassette player, CD player and electric lights for various purposes on the car, and it is convenient to convert electrical energy into mechanical energy, sound energy, light energy, etc. 4.Tanker truckAn iron chain is usually hung at the end of the road to the road. This is conducive to the rapid transmission of the charge generated by the bumps during the transportation to the ground, avoiding disasters caused by electrostatic discharge. 5. Car lights glow: electric energy-light energy Five, optics 1. The rear view mirror beside the car and the observation mirror at the intersection are all convex mirrors, which can broaden the field of vision 2. When the car is driving at night, the lights in the car are generally not turned on, which can prevent the passengers in the car from imaging on the windshield in front of the driver and interfere with the correct judgment of the driver 3. The windshield in front of the car is usually not upright (except for cars with tall chassis). This is because the windshield is equivalent to a flat mirror and objects in the car are easily imaged in front of the driver through it, which affects the driver’s judgment. 4. CartaillightLampshade: The corner reflector can reflect the light that comes in to ensure the safety of vehicles behind 5. Car headlights: the principle of concave mirror reflection, the near-distance light filament is near the focal point, and the far-distance light filament is at the focal point The above content is collected into articles, intended to arouse readers, especially our junior high school students, to pay attention to and test life, because all discoveries are inseparable from life, and knowledge goes with everyone! Related: ·Vehicle Fuel Cell[汽车知识]
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