Question

a body of mass 10 kg is kept at a height 10 m from the ground when it released after sometime is kinetic energy become 450 joule.what will be the potential energy of the body at that instant

Answer 1

PE (Potential Energy)= mgh
=10×10×9.8
=980 joule

Answer 2

$\bf{\underline{\underline{Answer:}}}$

$\bf{\therefore \:550\:J}$

$\bf{\underline {Given:}}$

Mass of body, $m \:= \:10\: kg$

Kinetic energy, $K.E.\:= \:450 \:J$

Initial velocity of the body, $u= 0\: m{s} ^{-2}$

Height,$\: h \:= \:10 \:m$

Now, the mechanical energy of the body

= Potential energy + Kinetic energy

$E = mgh + \dfrac{1}{2}mu^2$

Substituting the values, we get:

E = 10 x 10 x 10 = 1000 J

After sometime kinetic energy is 450 J.

Suppose instant potential energy is U, then

By law of conservation of energy,

E= 450 + U

Substituting the values, we get

1000 = 450 + U

$\bf U = 1000 - 450 = 550\: J$