A mechanical device requires 420 J of work to do 230 J of work in lifting a crate. What is the efficiency of the device?

Question

A mechanical device requires 420 J of work to do 230 J of work in lifting a crate. What is the efficiency of the device?  
I keep getting 0.5% am I right?

Henry · Accepted Answer

Eff. = (Output/Input)*100% =(230/420)*100 = 54.8%

Anonymous · Answer

I am wondering the same thing