SOLUTION: A vehicle of mass 1325 kg and a co efficient of a friction between the grounds/tires is 0.4. what is the maximum retarding force which can be used to stop it without skidding

To find the maximum retarding force that can be used to stop the vehicle 
without skidding:

Maximum retarding force = Coefficient of friction x Normal force

The normal force is the force exerted by the ground on the vehicle, which is
equal to the weight of the vehicle.

Weight of the vehicle = Mass x Acceleration due to gravity
Weight of the vehicle = 1325 kg x 9.8 m/s2 = 12997.5 N

Now, we can calculate the maximum retarding force:

Maximum retarding force = Coefficient of friction x Normal force
Maximum retarding force = 0.4 x 12997.5 N = 5199 N

Therefore, the maximum retarding force that can be used to stop the vehicle
without skidding is 5199 N.

Edwin