A 3858 N piano is to be pushed up a (n) 3.49 m frictionless plank that makes an angle of 31.6 ◦ with the horizontal. Calculate the work done in sliding the piano up the plank at a slow constant rate. Answer in units of J.

Question

Physics

Rayne

18 February, 14:12

A 3858 N piano is to be pushed up a (n) 3.49 m frictionless plank that makes an angle of 31.6 ◦ with the horizontal. Calculate the work done in sliding the piano up the plank at a slow constant rate. Answer in units of J.

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Brooke Arellano · Answer 1

The work done will be equal to the potential energy of the piano at the final position

P. E=m. g. h

. consider the plank the hypotenuse of the right triangle formed with the ground

. let x be the angle with the ground=31.6°

. h be the side opposite to the angle x (h is the final height of the piano)

. let L be the length of the plank

sinx=opposite side / hypotenuse

= h/L

then h=L. sinx=3.49*sin31.6°=0.638m

weight w=m. g

m=w/g=3858/10=385.8kg

Consider Gravity g=10m/s2

then P. E.=m. g. h=385.8kg*10*0.638=2461.404J

then Work W=P. E.=2451.404J