calculus II/physics work problem

Question

Given:

Particle moves 150ft in a straight line

Particle is acted upon by a constant force of 10lb in the opposite direction

 

What is the work done by the force?

Answer 1

As The displacement is in the opposite direction

Work done is negative

so W = - 10*150*g = - 1500 *32= - 48000 lb_f ft