Coupon Accepted Successfully!


Centripetal Force

According to Newton’s second law of motion, a change in the direction of motion of the body can take place only if some external force acts on the body.
Since everybody has directional inertia, a velocity cannot change by itself and as such we have to apply a force. But this force should be such that it changes the direction of velocity and not its magnitude. This is possible only if the force acts perpendicular to the direction of velocity (Fig. 1). Because the velocity is along the tangent, this force must be along the radius (because the radius of a circle at any point is perpendicular to the tangent at that point).
Fig. 1
Such force moves the body in a circular path. It must act toward the center. This center-seeking force is called the centripetal force. Hence, centripetal force is the force which is required to move a body in a circular path with uniform speed. The force acts on the body along the radius and towards center.
  • Formulae for centripetal force:
  • Centripetal force in different situations:
Centripetal force
A particle tied to a string and whirled in a horizontal circle.
Tension in the string.
Vehicle taking a turn on a level road.
Frictional force exerted by the road on the tyres.
A vehicle on a speed breaker.
Weight of the body or a component of weight.
Revolution of Earth around the Sun.
Gravitational force exerted by the Sun.
Electron revolving around the nucleus in an atom.
Coulomb attraction exerted by the protons in the nucleus.
A charged particle describing a circular path in a magnetic field.
Magnetic force exerted by the agent that sets up the magnetic field.

Test Your Skills Now!
Take a Quiz now
Reviewer Name