Answer : The mechanical energy of the rock is, 134 J
Solution :
As we know that the mechanical energy is equal to the sum of the kinetic energy and the potential energy.
The formula used for mechanical energy is,
[tex]M.E=K.E+P.E\\\\M.E=(\frac{1}{2}mv^2)+(mgh)[/tex]
where,
M.E = mechanical energy
K.E = kinetic energy
P.E = potential energy
m = mass of an object = 2 Kg
v = velocity of an object = 6 m/s
h = height = 5 m
g = acceleration due to gravity = [tex]9.8m/s^2[/tex]
Now put all the given values in the above formula, we get the mechanical energy of the rock.
[tex]M.E=[\frac{1}{2}(2Kg)\times (6m/s)^2]+(2Kg\times 9.8m/s^2\times 5m)=134\text{ Kg }m^2s^{-2}=134J[/tex]
Therefore, the mechanical energy of the rock is, 134 J
