The Second Jiujiang Yangtze River Bridge (picture A) will be opened to traffic by the end of this year. Its completion will greatly promote the construction of "Binjiang New City" in Xiaochi Town and

The Second Jiujiang Yangtze River Bridge (picture A) will be opened to traffic by the end of this year. Its completion will greatly promote the construction of "Binjiang New City" in Xiaochi Town and make Xiaochi Town a

(1) The pressure of the concrete pump truck on the ground:

F=G=mg=49×103kg×10N/kg=4.9×105N,

∵The maximum pressure of the vehicle on the ground is 7×105Pa,

∴From p=FS, the minimum total contact area between the 16 wheels and the ground:

S=Fp=4.9× 105N7×105Pa=0.7m2;

(2) The volume of concrete delivered by the pump per hour:

V=200m3,

It can be obtained from ρ=mV , the mass of concrete:

m′=ρV=2.7×103kg/m3×200m3=5.4×105kg,

The work done by the delivery pump on concrete per hour:

W=G′h=m′gh=5.4×105kg×10N/kg×240m=1.296×109J;

(3) Work done by the pump per hour:

W pump=Wη=1.296×109J60%=2.16×109J,

Power of delivery pump:

P=W pump t=2.16×109J3600s=6×105W= 600kW.

Answer: (1) The total contact area between the concrete pump truck and the ground shall not be less than 0.7m2;

(2) The work done by the delivery pump on the concrete per hour is 1.296×109J;

(3) The power of the delivery pump is 600kW.