Physics
Friction is reduced by :
- making the surfaces wet
- making the surfaces dry
- making the surfaces rough
- sprinkling sand on the surface.
Related Questions
A force to be expressed correctly requires :
- only the magnitude
- only the direction
- both the magnitude and direction
- none of the above.
Friction :
- promotes motion
- opposes motion
- acts in the direction of motion
- is always a nuisance.
Friction :
- causes wear and tear
- produces heat
- stops a moving body
- has all the above disadvantages
Friction is increased if :
- an oil is sprayed
- the surfaces are made wet
- the surfaces are made dry
- the surfaces are polished