Question

An object of mass 5kg falls from rest and has a kinetic energy of 1500J midway its journey.
a) what is its potential energy at this point?
b) what is the potential energy it started with?
c) what is it’s kinetic energy before hitting the ground?

Answer 1

Answer:

a) 1500 j

b) 3000 j

c) 34.64 m/s

Explanation:

at halfway point 1/2 of the potential energy has been converted to kinetic energy

so 1 /2 P E =  1500 j

   it will still have the OTHER half of its PE     1500 j

c) PE will be entirely converted to KE when it is at the bottom

       KE = 1/2 m v^2

       3000 = 1/2 (5)(v^2)     show   v = 34.64 m/s