Question

A mass of 5kg falls a building 40 high
What is its potential energy of the building?
What potential and kinetic energy will the object have at 10m from the ground?

Answer 1

POTENTIAL ENERGY : PE

MASS : m = 5

HEIGHT : h = 40

ACCELERATION DUE TO GRAVITY : g = 10

PE = mgh

     = 5×40×10

     = 2000 Joules

KINETIC ENERGY : KE

KE = 1/2 × m × v²                          [ using third equation of motion, v²=u²+2gh]

     = 1/2×5× 80

=    2000 J

                                           { u = 0m/s  g and h are mentioned above }

THANK YOU .