A force is known as conservative, if its work depends only on the initial and final positions, regardless of the path followed. Two examples of conservative forces are the weight of a body and the spring force. Weight is the force experienced by an object due to gravity. If the block hanging from a crane is displaced against gravity by a vertical displacement of dr, then work done is the dot product of the force and the vertical displacement. The work done is negative as the weight acts in the opposite direction of the displacement. Since the work done is independent of the path taken and only depends on the vertical displacement, the weight is a conservative force. Similarly, for linearly elastic springs, when a block is displaced horizontally, the work depends only on the spring's initial and final positions, and is independent of the path taken. So, the forces exerted by springs are also conservative.