Is the work done by non-conservative forces always negative? Discuss.

$A$ particle moves in a one-dimensional field with total mechanical energy $E$. If the potential energy of the particle is $V(x)$,then:

When a conservative force does positive work on a body,then the

$A$ body with mass $2\, kg$ moves in one direction in the presence of a force which is described by the potential energy graph. If the body is released from rest at $x = 2\, m$,then its speed when it crosses $x = 5\, m$ is ................ $m/s$.

The potential energy of a particle varies with distance $x$ as shown in the graph. The force acting on the particle is zero at

In the case of conservative forces,what physical quantity is represented by the negative value of the derivative of potential energy with respect to position?