"Work done by a constant force on an object is the product of the force and the distance moved by the object in the direction of the force" -textbook
There is work done ONLY if the direction of the force and the direction the item is moving are the same. In figure A, the direction of the force (the lifting) is upwards (defying gravity), and the book is moving upwards, so work is done. In figure B, the force is still moving upwards (the person is carrying the books) but the book is moving to the right, so there is NO work done.
Answer:
Elements and compounds are two types of pure substances.
Explanation:
Answer: A dune is a mound of sand formed by the wind, usually along the beach or in a desert. Dunes can also be formed by strong currents beneath the water.