Question

How could you increase the sliding friction between the sled and track? How could you decrease it?​

Answer 1

Answer:

You could put sheet metal lining the bottom or something similar to that

Explanation:

Answer 2

Explanation:

If the normal force is the weight of objects you are sliding across the floor, adding or subtracting weight will increase or decrease the sliding friction. But also, if you are pulling an object with a rope, pulling at an upward angle will reduce the normal force.