A mover hoists a 200 kg piano from the ground to a height of 10 m using a single pulley. What was the change in the pianos energy? a. 20j b. 200j c. 2000j d. 20000

Answer: d. 20000 JExplanation:Potential energy is the energy possessed by an object by virtue of its position.[tex]P.E=m\times g\times h[/tex]m= mass of object = 200 kgg = acceleration due to gravity = [tex]10ms^{-2}[/tex]h = height of an object 1. when h= 10 m[tex]P.E=200\times 10ms^{-2}\times 10m=20000Joules[/tex]2. when h= 0 m[tex]P.E=200\times 10ms^{-2}\times 0m=0Joules[/tex]Thus change in energy=(20000-0)Joules=20000Joules.

P.E= Mass x gravity x height   (standard gravity = 10m/s approaximately)     = 200x10x10= 20000j (D)