a) In which case is the pulling easy? Why?

Question

Effect of rollers on friction. Pull a suitcase without rollers and pull a suitcase which has rollers.

a) In which case is the pulling easy? Why?

b) What do you notice ? In which case is it easy to pull the book? Why?

Answer 1

a) It is easy to pull when suitcase has rollers.

Try to push a book lying on the table. Now place the book on two to three pencils or pens without caps. Push the book again.

b) 

In the second case it is easy to pull the book. The reason is it is always easier to roll a body than to slide it over a surface.