Tag: turning effect of force

A couple is defined as a pair of two equal and opposite parallel forces acting along two different lines. A couple can produce roatation in the body but not the translational motion. A single force can produce translation motion in the body. Thus the given statement is true that a couple can never be replaced by a single force.

Couple tends to rotate the body but it does not produce translational motion. Thus the given statement is false.

A couple is defined as a pair of two equal and opposite parallel forces acting along two different lines. Since net force acting on the body is zero, so the body is in translatory equilibrium. A couple produces torque which rotates the body. Thus the given statement is true that only a couple can produce pure rotation in a body.

A couple has to be applied to the tap in order to open it. A couple is the combination of two equal and opposite parallel forces acting at different axes. Thus option D is correct.

$\left[ MOI \right] =\left[ M{ R }^{ 2 } \right] =\left[ { M }^{ 1 }{ L }^{ 2 }{ T }^{ 0 } \right] \ \left[ Pressure \right] =\left[ N/{ M }^{ 2 } \right] =\left[ { M }^{ 1 }{ L }^{ -1 }{ T }^{ -2 } \right] \ \left[ Couple \right] =\left[ N.{ M } \right] =\left[ { M }^{ 1 }{ L }^{ 2 }{ T }^{ -2 } \right] $

$Power\quad P=100kW\quad =100000W\ w=1800\times \cfrac { 2\pi  }{ 60 } \quad rad/s\ \quad =60\pi \quad rad/s\ P=torque\times w\ torque=530.5\quad Nm$

a couple produces rotational motion of a body . 

While opening a tap with two fingers, a couple should be applied which is defined as a pair of parallel equal forces acting in opposite direction about two different axis.

Two equal and opposite forces are applied about different axis, which is termed as couple, to unwind a screw.