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Relation between Torque, Speed, power etc. respect to a electric car

  1. Nov 20, 2013 #1
    hey guys,

    I am building an electric go kart for a final project, and i'm just trying to get my initial justifications correct, with respect to the classical physics involved.

    SPECS: i was the car to be able to reach 15km/h,
    The total weight of the car will be approx 200kgs.
    the size of the tires of the car are 30 cm in diamator.

    Motor Type: BLDC Motor
    Maximum Power: 350 Watt
    Max. Operating voltage: 48v

    so i need to calculate the torque... at the wheels , and then decide on the gearing ratio! this decision is obviously indicative on the parametors of the motor i have! and the goals i want to achieve! The Motor i have has a max RPM of 4000, and a peak torque of 12NM.

    can anyone show me best how to perform these calculations ? i understand that i need acceleration ! can i assume constant acceleration ? if that is the case can i just say i would like the car to accelerate to 15km/h in 10 seconds

    ... any help will be much appreciated !
    Thank You
  2. jcsd
  3. Nov 22, 2013 #2
    If this is your final project these should be easy to figure out -

    1 estimate speed of the go-cart to the rpm of the wheel, then compare to the motor max speed.

    2 acceleration will depend on the torque and then force where the wheel meets the road...
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