All Physics Formulas for Grade 8:
1. Gravity (G): the Earth's attractive force on an object, which is calculated as G=mg, where m is the mass of the object.
Explanation: Gravity is the Earth's attraction to an object, and its magnitude is equal to the object's mass multiplied by its gravitational acceleration.
2, pressure (p): the pressure per unit area of the object, the formula is p = F / S, where F is the force acting on the object, S is the force area of the object.
Explanation: pressure is a physical quantity that describes the pressure exerted on an object per unit area, which is equal to the force acting on the object divided by the area of the object subjected to the force.
3, buoyancy (F_float): the object in the liquid upward force, the formula for its F_float = ρVg, where ρ is the density of the liquid, V is the volume of the object.
Explanation: buoyancy is a physical quantity that describes the upward force exerted on an object in a liquid, and it is equal to the density of the liquid multiplied by the volume of the object multiplied by the acceleration due to gravity.
4, heat (Q): the heat absorbed or released by the object, which is calculated as Q = cm Δt, where c is the specific heat capacity of the material, m is the mass of the object, Δt is the amount of change in temperature.
Explanation: Heat is a physical quantity that describes the amount of heat absorbed or given off by an object, and it is equal to the change in temperature multiplied by the mass of the object multiplied by the specific heat capacity of the substance.
5, speed (v): indicates the speed of movement of an object, the formula is v = s / t, where s is the distance moved by the object, t is the time required for movement.
Explanation: speed is a physical quantity that describes the speed of an object's movement, which is equal to the distance the object moves divided by the time required for the movement.
Physics in life:
1, energy use: Physics knowledge can help us understand the nature of energy and how it is utilized, such as solar energy, wind energy, water energy, etc., as well as how to develop new sources of energy through physical principles. For example, solar panels are designed and manufactured based on the principle of photovoltaic effect, which provides renewable energy by capturing the sun's light energy and converting it into electricity.
2. Medical equipment: Knowledge of physics can be used to design a number of medical devices, such as X-ray machines, CT machines, magnetic **** vibration imaging (MRI), and medical instruments used to diagnose diseases. For example, MRI equipment utilizes magnetic fields and radiofrequency pulses to produce images of the inside of the body to help doctors diagnose diseases.
3. Transportation: Knowledge of physics can be used to design a number of transportation vehicles, such as cars, trains, and ships, as well as equipment used to control and manage traffic flow. For example, the design of automobiles requires consideration of physical knowledge in areas such as mechanics and materials science to ensure the safety and stability of the vehicle.
4. Communication technology: Knowledge of physics can be used to design a number of communication devices, such as television, telephone, and satellite communications, as well as equipment used to transmit information. For example, the satellite communication system utilizes physical principles to transmit signals with wide coverage for different areas and different users.
5. Industrial applications: Knowledge of physics can be used to design a number of industrial equipment and machines, such as machine tools, elevators, and automated production lines, as well as equipment used to control and manage production processes. For example, the design of an elevator needs to take into account the physical knowledge of mechanics and electricity to ensure the safety and stability of the elevator.