Question

A 1300 kg. wrecking ball hangs from a 12 m -long cable. The ball ispulled back until the cable makes an angle of 28.0 with thevertical.
By how much has the gravitational potential energy of the ballchanged? ΔU=_________
Express your answer to two significant figures and include theappropriate units.


Can you please help or check the answer...I was marked wrong when Iput this answer in 2 sig figs

= 1.5*10^{3 J}

RE: change in gravitational potential energy
Answer Details
when the ball is mean position that means horizontal (h = 0) thenthe intial potential energy,
P.Ei = mgh = 0
if the ball is reaches height 'h' then the final potentialenergy,
P.Ef = mgh = mgl(1-casθ) = 1300*9.8*0.117
= 1491.24 J
therefore ΔP = Pef-Pei =1491.24 J