Question

The power expended when a 10 N barbell is raised 2. 0 m in 2s is

Answer 1

Work done = (force) x (distance)
                   = (10 N)  x  (2  m)         =     20 joules . 
                    
 Power = (work done) / (time to do the work)
             =          (20 J)  /  (2 sec)
             =            10 joules/sec        =      10 watts .