a)P.E=mass x gravity x height
=20x4x9.8
784kgm*2/s*2.
b)kinetic energy gained =Potential energy lost
1/2x20xv*2 =784kgm*2/s*2
20v*2=784.
v*2=78.4
v=8.85m/s
king1992 answered the question on June 29, 2018 at 07:18
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