JSS 2: WORK

Work is the product of force and the distance moved in the direction of the force.

Work is done only when there is displacement in the direction of the applied force. It is a scalar quantity.

Work = Force x Distance 

Force = mass(m) x acceleration due to gravity (g)

Force =mg

Work = Force(mg) x Distance (h)

          = mgh

S.I unit of work is Newton-meter(Nm) or Joule (J)

Example 1: A person pushes a box with a force of 50 N over a distance of 5 m in the same direction. How much work is done?

Solution:

Work = Force x Distance

          = 50N x 5m

          = 250Nm

Example 2: An object is horizontally dragged across the surface by a 100 N force acting parallel to the surface. Find out the amount of work done by the force in moving the object through a distance of 8 m.

Solution:

Work = Force x Distance

          = 100N x 8m

          = 800J

Example 3: A truck of 12kg raised vertically through a height of 10.6m. What is the work done? (g=10m/s)

Solution:

Force= mass x acceleration due to gravity

        F= m x g

          = 12kg x 10m/s

          = 120N

Work = Force x Distance

          = 120N x 10.6m

          = 1272J