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I'm trying to find the torque required of an electric vehicle to pull a 1000kg trolley on four Nylon Wheels on smooth concrete. The trolley fully supports its own weight. The vehicle has 2 rubber drive wheels of Radius( r = .125m). Now I'm not sure if am on the right track because i cant find much information on Rolling resistance.

Using Fr = Crr * N to find the rolling resistive force.

Where Fr = Rolling resistance force

Crr = coefficient of rolling resistance

N = Normal force

Rolling resistance of trolley

Assuming Crr = .004

N = 1000kg * 9.81 m/s^2

Ft= (.004*9810) = 39.24

rolling resistance of vehicle

Fv = (45kg * 9.81 m/S^2 * .08)

Fv = 35.316

Ftotal = Fv +Ft

Ftotal = 35.316 + 39.24 = 74.6N

So if I use the equation for toque

T = F * r

T = 74.6 * .125

T = 9.32 N.m

This should give me the minimum required torque to get the trolley and vehicle rolling on a smooth horizontal surface. Yes/No?

Also if my system were to reach maximum velocity of 5km/h (1.389m/s) how do I find the torque needed.

Regards

tcitizen

PS I've tried to include as much information as possible.

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# Torque and Rolling Resistance

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