You do 25 j of work to move a 4 n object 5 meters. find your efficiency

Efficiency is defined as "it is the ratio  of output to the input

input work  = 25 J ,

output work = (4 × 5) = 20 J  ,

                                           Work  =Force × distance moved

                                                       = 4 × 5

                                                        = 20 J  

                 efficiency (η ) = 20 ÷ 25

                                          = 80%

Efficiency is 80%              

b.a device that inputs heat into a cool object

f=ma newton

f=100x2.5=250n