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课程最新笔记

Time Line为什么距离是速度时间曲线下方的面积的笔记
微分无限的思想
质量和重力的区分的笔记
Mass is how much stuff there is of something, how does something response to a specific force with Newton's second law.Weight is the force of gravity on a mass or on an object.The force of gravity between two objects is going to be a G which is F=G(m1*m2/r^2).F equals G(m1/r^2) which the "m1" is the mass of the earth, the "r" is the distance from the center to surface that we can get the g=9.8m/s^22. So the gravitional field of earth is 9.8 m/s^2.So the weight is the gravitional field of earth times the mass.The unit of mass is "kg", the unit of weight is the unit of gravitional field which is "m/s^2" times "kg".Then final unit of weight is kg*m/s^2 which is the unit of Newtons, force.If we take the new weight on the Moon which we can get the different gravitional field of Moon than on Earth. But we can still multiply the mass with the gravitional field of moon.Earth is not a perfect "ball", there is different weight in different places in the Earth.England and the United States have different units in weight and mass. The mass is "slug", and the weight is "pound".
重力介绍的笔记
You can change everything with as same as gravity, like temperature, or everything theory much like gravity.Gravity is immaterials.The row and the column.By the mass?Force=G*(m1*m2/r2).G=Newtons*(m/kg)^2;"g" as the gravitational field at the surface of Earth which is 9.8 m/s^2;Double force, the third law of the Newtons.
恒加速下的平均速度的笔记
"Positive sign" is to right, the "Negative sign" is to left. Same as up and down.How far is gone when it is acceleration, multiply the acceleration and changing time.Final velocity is the intial velocity plus the areas that go when it's acceleration, which is multiply the acceleration and changing time.V(intial)+(t)a=V(final);When at begining the speed is constant velocity, then suddenly change into acceleration which the speed is changing over time.The final the displacement is the constant velocity times changing time add the sum of final velocity-initial velocity over 2 then times changing time.The graph can help solve the problem how far is object gone.Average acceleration is 1/2 times the sum of initial velocity plus final velocity.The displacement when the speed is acceleration, is the changing time times the average velocity.