Force Types- Frictional , Centripetal,Centrifugal, Adhesion, Cohesion Forces

Force Types- Frictional , Centripetal,Centrifugal, Adhesion, Cohesion Forces FORCE An influence that changes the state of rest in a straight line of a body is called - Force  Ans : F = ma [m = mass, a = acceleration] Unit - Newton or Kg m/s2  CGS unit - Dyne  One Newton = 10^5 dyne  Strongest force in the universe  Ans:Nuclear force  Weakest force in the universe  Ans:Gravitational Force  Force acting for a short time  Ans:Impulsive force CENTRIPETAL FORCE AND CENTRIFUGAL FORCE CENTRIPETAL FORCE Force which acts on a body moving in a circular path and it is directed towards centre is called Ans:Centripetal force eg: Vehicle moving round a curved road requires this force (when speed increases, more centripetal force is required) CENTRIFUGAL FORCE Force that acts on a body moving in a circular path and is directed away from the centre is called Ans:Centrifugal force eg : This force helps to separate cream from milk Capability of rotating objects around a fixed axis is called  Ans:Torque eg : Tightening of nut FRICTIONAL FORCE Force that resists the movement of one surface over another is called  Ans:Frictional Force The substances which reduce the frictional force between moving surfaces Ans:Lubricants eg : Grease, Oil, Graphite etc. APPLICATIONS OF FRICTION     We can walk on ground Car can stop with a sudden brake Slow landing of a parachute through air TYPES OF FRICTIONAL FORCES Static friction Ans:Force acts in a direction opposite to the direction of motion Kinetic friction Ans:Force occurs when two objects are moving relative to each other or rub together Rolling friction Ans:Force acts when two bodies role one another eg : Ball bearing operation ADHESION FORCE Force of attraction between unlike molecules is termed as Ans:Adhesion eg : water drop sticks on glass surface COHESION FORCE   Force of attraction between like molecules is termed as Ans:Cohesion eg: water molecules join together