If a force of 250N is applied to a piano being pushed up a ramp at an angle of 18degrees above the horizontal, what force is being applied to lift the piano?

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

the answer is c.)

explanation: