Two piano movers are bringing a piano into a home. One mover pushes to the right with a force of 310 N, while the other pulls to the right as well, but with a force of 270 N. The
force of friction acts to the left, with a magnitude of 190 N. The piano weighs 2500 N.
What is the net force on the piano?

i don't understand is there any other way you can rephrase it plz let me know in the comments and i will do it.

explanation:

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.