Answer :
6160 joules
to lift 1 newton 1 metre requires 1 joule
there are 10 newtons in one kilo
so 77(kg) x 8 (metres) x 10 (newtons/kilo) = 6160 joules
to lift 1 newton 1 metre requires 1 joule
there are 10 newtons in one kilo
so 77(kg) x 8 (metres) x 10 (newtons/kilo) = 6160 joules