lucky_star said:
tiny-tim said:Hi lucky_star! Welcome to PF!
Why have you used only one value of F?
F has different values as x changes.
lucky_star said:
tiny-tim said:Noooo …
Look at the graph!
The force is 0.8N only for x ≤ 0.50m.
Try again.
Woohoo! 
)lucky_star said:
tiny-tim said:You tell me!
lucky_star said:
Work done by a variable force is the measure of the amount of energy transferred when an object is moved by a force that changes in magnitude and/or direction. It takes into account the varying force applied over a distance.
The work done by a variable force is calculated by integrating the force function over the distance travelled by the object. This can be represented by the equation W = ∫ F(x) dx, where W is the work done, F(x) is the force function, and dx is the distance travelled.
The main difference between work done by a constant force and a variable force is that with a constant force, the force remains the same throughout the entire distance, while with a variable force, the force changes at different points along the distance. This results in different amounts of work being done.
Some examples of variable forces in real life include pushing a shopping cart, throwing a ball, or rowing a boat. In each of these situations, the force applied changes in magnitude or direction as the object moves.
The angle between the force and displacement affects the work done by a variable force by changing the amount of force that is acting in the direction of the displacement. When the angle is 0 degrees, all of the force is acting in the direction of displacement, resulting in the maximum amount of work. As the angle increases, the amount of force acting in the direction of displacement decreases, resulting in less work being done.