Does 200 Foot-Pounds of Work Require More Work?

[jonathan.15]

You lift a 50 lb weight by a distance of 4 ft so you do 200 foot-pounds of work. You then hold the weight and walk a horizontal distance of 4 feet, does this require an additional 200 foot-pounds of work? Please excuse the units, this question came from a calculus book.

 

[dreamLord]

The simple answer would be ; no. This is because the force your hand applies perpendicular to the direction of motion of the weight. The definition of work involves a dot product, which is zero for 2 perpendicular vectors.