Which of the following will produce the maximum friction?

If the static friction between two surfaces X and Y is found to be 20 N, then the rolling friction between these two surfaces should most likely be :

If the static friction between two surfaces P and Q is measured to be 50 N, then the sliding friction between these two surfaces is most likely to be :

Four similar cars having exactly the same mass are running at the same speed on the same road when brakes are applied at the same time. The cars come to a stop after covering distances of 5 m, 5.5 m, 4.8 m and 5.2 m respectively. The friction between the brake pads and discs will be the maximum in the car which travels the distance of:

The weight of an object can be measured by a: