We can easily walk on a frictionless surface as friction would not be present to oppose our motion.
Can you walk on a frictionless surface ? Why / Why not ?
Why is it difficult to walk on Sand ? (a) Because Sand is soft and does not oppose motion (b) Because Sand is soft and opposes motion (c) Because Sand does not yield high Reaction forces required for Walking (d) Because Sand yields Reaction forces required for Walking.
We can easily move our hand in the air, but not through a solid block of wood because