An electric vehicle has the following parameters: Vehicle mass: 1200 kg Total mechanical transmission efficiency: 94%...

 

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An electric vehicle has the following parameters: Vehicle mass: 1200 kg Total mechanical transmission efficiency: 94% Wheel radius: 0.32 m Gear reduction ratio: 5:1 Aerodynamic drag coefficient: 0.3 Frontal area: 1.7 m² Rolling resistance coefficient: f = 0.009 (1+). vehicle speed in km/h Density of air: 1.22 kg/m² a. Calculate the shaft torque and the shaft speed of the electric motor when the vehicle travels on a flat road with 160 km/h cruising speed. b. At what speed is the rolling resistance equal to the wind resistance? c. At what speed is the wind resistance twice of the rolling resistance? An electric vehicle has the following parameters: Vehicle mass: 1200 kg Total mechanical transmission efficiency: 94% Wheel radius: 0.32 m Gear reduction ratio: 5:1 Aerodynamic drag coefficient: 0.3 Frontal area: 1.7 m² Rolling resistance coefficient: f = 0.009 (1+). vehicle speed in km/h Density of air: 1.22 kg/m² a. Calculate the shaft torque and the shaft speed of the electric motor when the vehicle travels on a flat road with 160 km/h cruising speed. b. At what speed is the rolling resistance equal to the wind resistance? c. At what speed is the wind resistance twice of the rolling resistance?