Answer:
[tex]154.9KJ[/tex]
Explanation:
The mechanical Energy associated with a body, is the sum of the potential(Energy due to its position) energy and the kinetic energy(energy due to its motion).Hence ewe can write as
[tex]Mechanical Energy, M.E=Potential Energy(P.E)+Kinetic Energy(K.E)\\[/tex]
The expression for the potential Energy is
[tex]P.E=mass*acceleration*height\\P.E=mgh\\[/tex]
while the expression for the Kinetic Energy is
[tex]K.E=\frac{1}{2}*mass*(velocity)^{2}\\K.E=(1/2)mv^{2} \\[/tex]
since the Height,h=12m,
mass,m=1200kg,
acceleration,g =9.8
and velocity,v=4.8m/s
we can compute the Mechanical energy in kJ as
[tex]M.E=mgh+(1/2)mv^{2}\\ M.E=(1200*9.8*12) + (1/2)(1200*4.8^{2} )\\M.E=141120 + 13824\\M.E=154944J\\M.E=154.9KJ[/tex]
