The definition of work done, in some science books, is written as force x distance. This is incorrect.
The true definition is Work Done = Force x Displacement (W.D = F x s).
Suppose we move an object of mass m = 6kg (resting on the earth) against gravity g (approximately 10 m/s/s).
Let the distance moved = 20m and assume the object comes to rest 5m above the earth.
Then the total Work Done = F x s = mg x s = 6 x 10 x 5 = 300 J (joules).
Notice that this is also equal to the increase in gravitational potential energy of the object. Also note that force and displacement are vector quantities whilst work done is a scalar quantity.
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