Question

It is more difficult to walk on a sandy road than on a concrete road because

Answer 1

it is more difficult to walk on a samdy road than on a concrete road because sand is slippery and dont have strong base ,whereas concrete has strong base and it will remain solid because it has solid base..

Answer 2

Concrete  is  a  solid  surface   and  can  bear  a  lot  of  weight.It  can  handle   a  big   thrust(force  acting  perpendicular  to  the  surface)   acting  on  it.If  you  want  to  walk on  sand  don't  wear  high  pointed  shoes  or  sandals  as  they  will  increase  the  concentration  of  thrust  at  a  point.    You  won't   be  abe  to  walk  properly.Wear  shoes  or  sandals  with  flat  soles.
With  increase  in  surface  area  the  imapct  of  pressure  will  decrease  thus  allowing  you  to  walk  easily  on  the  sand.