Aperson pushes a box up a ramp that is 3m long and 1 m high if the box has a mass of 20 kg and the person pushes with a force of 80 n what is the efficiency of the ramp

The efficiency of the ramp11%

Explanation:

Let AC be the length of inclined plane or ramp = 3m (given)

BC be the height through which the load is lifted = 1m.

Load or Box (L) = 20kg  

= 20×9.8 N = 196N

Effort (E) =  

= 196 ×0.33 =64.68

where θ is the angle between AC and AB.

Therefore,

Mechanical Advantage (MA) =  

MA = 0.33.

Now, Velocity Ratio (VR) =

=  

= 3/1 = 3  

Efficiency =

=  

=0.11 = 11% which is the efficiency of the ramp

i think it's letter a.