answer
77.25 N
explanation
(look at picture for free body diagram)
the force on the piano has both vertical and horizontal components, and since the questions asks about the force to lift the piano, we want to find the vertical component
we can use trigonometry where sinA = opposite/hypotenuse
A = 18 degrees
hypotenuse = 250 N
sin18 = opposite (vertical component) / 250
vertical component = sin18 * 250
= 77.25 N
