A 5.0-kg object is pulled along a horizontal surface at a constant speed by a 15-N force acting 20 above the horizontal. How much work is done by

A 5.0-kg object is pulled along a horizontal surface at a constant speed by a 15-N force acting 20° above the horizontal. How much work is done by this force as the object moves 6.0 m?

a.     78 J

b.     82 J

c.     85 J

d.     74 J

e.     43 J