Answer:
50 percent
Step-by-step explanation:
The efficiency of ramp can be found by using this formula
(Output work/input work)*100.
Amounts of work to lift up = 600j
Amount of work bro take up to same height = 1200j
Efficiency of ramp = (600j/1200j) * 100
= 0.5 x100
= 50 percent
Therefore from the calculations above, the efficiency of this ramp is 50 percent