Physical power calculation The mass of a car is 1.2t, the rated power is 80kW, and the car runs at 36km / h. then it accelerates and reaches the maximum speed of 180km / h after passing 700m. If the resistance in the process of driving remains unchanged, the calculation method is as follows The resistance of the road to the car Work done by the car during acceleration

Physical power calculation The mass of a car is 1.2t, the rated power is 80kW, and the car runs at 36km / h. then it accelerates and reaches the maximum speed of 180km / h after passing 700m. If the resistance in the process of driving remains unchanged, the calculation method is as follows The resistance of the road to the car Work done by the car during acceleration

Look up the book and read it carefully. It's not difficult to do this problem

On the calculation of electric energy
When calculating the energy produced by the motor, we use the formula w = uit instead of W = I ^ 2rt. But when u and I take certain values and substitute them into these two formulas, the results are not the same?

This is because the most intuitive physical quantities that can be measured in the experiment (real life) are voltage and current, so the formula is expressed like this