When a car runs at a constant speed of 72km / h for 10 min, the consumption of gasoline is 1.2kg. When the car runs at a constant speed, the traction force F = 1200n, the consumption of gasoline is 1.2kg A car runs at a speed of 72km / h for 10 min at a constant speed, and consumes 1.2kg of gasoline. The results show that the traction force F is 1.2x103n and the calorific value Q of gasoline is 4.6 x107j / kg. Q: (1) What is the power consumed by the car during this period (that is, the heat released by the complete combustion of gasoline in one second)? (2) What is the power of the car's traction during this period? (3) Compare the results of (1) and (2), what do you find? Briefly analyze the reasons (write two).

When a car runs at a constant speed of 72km / h for 10 min, the consumption of gasoline is 1.2kg. When the car runs at a constant speed, the traction force F = 1200n, the consumption of gasoline is 1.2kg A car runs at a speed of 72km / h for 10 min at a constant speed, and consumes 1.2kg of gasoline. The results show that the traction force F is 1.2x103n and the calorific value Q of gasoline is 4.6 x107j / kg. Q: (1) What is the power consumed by the car during this period (that is, the heat released by the complete combustion of gasoline in one second)? (2) What is the power of the car's traction during this period? (3) Compare the results of (1) and (2), what do you find? Briefly analyze the reasons (write two).

(1) The heat released by complete combustion of automobile q = QM = 4.6 * 10 ^ 7 * 1.2 = 5.52 * 10 ^ 7 j the power consumed by automobile P = q / T = 5.52 * 10 ^ 7 J / (60s * 10) = 9.2 * 10 ^ 4 w (2) the distance passed by automobile in 10 min s = VT = 20 * 600 = 12000m the work done by automobile traction in 10 min w = FS = 1.2x10 ^ 3N * 12000m