Keisha writes that if an object has any external forces acting on it, then the object can be in dynamic equilibrium but not static equilibrium.

which statement best describes keisha’s error?
a)an object that is not moving is always in static equilibrium.
b)an object that is moving must be in dynamic equilibrium.
c)an object in either state of equilibrium must have no forces acting on it.
d)an object in either state of equilibrium must have no net force acting on it.

Before coming to the conclusion,first we have to know about the static and dynamic equilibrium.

As per Newton's first law ,a body continues to be at state of rest or of uniform motion along  a straight line as long as there is no external unbalanced force acting on it.

Hence if the net force is zero,the body  at rest will be at rest.This is called static equilibrium .Hence the condition for a body to be in static equilibrium is that sum of mechanical force is zero.

i.e

Again if the net force is zero,then velocity of the body won't be changed.Hence the acceleration of the body will be zero.This is called dynamic equilibrium where a body will move with uniform velocity  in the absence of net external force.

Hence if the net force is zero,then body will be both in static and dynamic equilibrium.

Hence the option  D  is right which  tells that a body in either state of equilibrium has no net force acting on it.

The answer  is D. on Edgen.

Explanation:

D. An object in either state of equilibrium must have no net force acting on it.

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.