Question

An object of mass 20 kg is dropped from a height of 4 m. Fill in the blanks in the following table by computing the potential energy and kinetic energy in each case. For simplifying
the calculations, take the value of g as 10 ms^-2. The total mechanical energy of the object remains _______.

Answer 1

P.E = mgh

= 20×4×10

= 800J

K.E= 1/2 mv²

= 1/2 ×20×0

=0J

total mechanical energy =K.E + P.E

= 0+800

=800j

take height as 3m 2m and 1m mechanical energy will be constant i.e 800j

so total mechanical energy of an object remains 800j