In recent days, Yixing municipal government has specially equipped a new type of electric patrol car for urban management and law enforcement bureau to further improve the level of urban management an

In recent days, Yixing municipal government has specially equipped a new type of electric patrol car for urban management and law enforcement bureau to further improve the level of urban management and improve the image of the city. ( 1)①∫P = 3kW = 3000 w，t= 10min=600s，

∴ power consumption: w = pt = 3000w× 600s =1.8×106j.

② The work done by electric patrol car to overcome resistance is: W Useful = W = 1.8× 106J.

∫m people =220kg, m cars =680kg,

∴ the total gravity of people and cars is: G=m total g=(m people +m cars) g = (20kg+680kg) ×10n/kg = 9000n.

The resistance of electric patrol car is 0.04 times of the total weight of people and cars.

∴ The traction force of electric patrol car when driving at a constant speed is: F=f=0.04G=0.04×9000N=360N.

The passing distance of patrol car is: s=W, f =1.8×106j360n = 5000m.

③∫S = 8× 10-2 m2，

∴ The pressure of people and vehicles on the ground is: P=F pressure S=GS=9000N9× 10? 2m2= 1× 105Pa。

(2)(2) Automobile regenerative braking can convert the mechanical energy consumed during automobile braking into electrical energy and store it, so automobile regenerative braking is equivalent to a generator;

(3) As can be seen from the image, when the car moves in a straight line at a uniform speed, the speed and kinetic energy remain unchanged. When the engine is turned off, the speed and kinetic energy decrease, but the kinetic energy is proportional to the square of the speed, so the image of kinetic energy and distance should be ②.

As can be seen from the image, under normal driving conditions, after the engine is turned off, the driving speed is 40m-30m =10m; When the regenerative brake is turned on, the driving distance is 34m-30m=4m, so the conversion efficiency into mechanical energy is 4m 10m=25=40%, so the energy storage efficiency is 1-40% = 60%.

So the answer is: (1)① The electric energy consumed by the motor is1.8×106j;

(2) The passing distance of patrol car is 5000m；;

(3) the ground pressure of people and vehicles is1×105 pa;

(2) generator;

(3)②; 60%.