How much work does it take to raise a #7 kg # weight #9 m #?

1 Answer
Dec 23, 2015

Answer:

#-630# #J#, considering acceleration due to gravity = #10# #m#/#s^2#

Explanation:

#"Work done = Force x Displacement"# x #costheta#
i.e. #W = F.s##costheta#

Here force acts opposite in the direction of displacement therefore #cos(180^@)# = #-1 #

Substituting #F = mg# we get #70# #kgm#/#s#, #s# = #9# #m#
We get
#7# x #10# x #9# x #(-1)# = #-630# #J#