Jawabanmu

2014-02-23T19:56:36+07:00
ΔEp = m . g . Δh
ΔEp = w . Δh
15000 J = 750 N . (50m-x)
 \frac{15000}{750} = (50m-x)
20 = 50-x
20-50=-x
-30 = -x
30m = x