Re: Shouldnt energy have component which makes it propotional to time involved?

Hello Rajmohan

Energy is a convienient measure of a systems ability to do work and like 
work it can be measured in joules.  There are two types of energy, 
potential and kinetic.  Potential energy is the energy stored in a body 
due to it's position, shape, or state.  Kinetic energy is the energy of 
motion and is usually defined as the amount of work a body can do as it is 
brought to rest.  Work is a product of a force acting on a body and the 
distance moved by it's point of application in the direction of the force. 

As I read your question, I think you are mixing work, energy and power.  
Power is defined as the rate at which work is done or energy is transfered 
and is typically measured in watts (joules/second) or horsepower.

In the first part of your example you describe a body suspended some 
distance above the earth.  In this case, the potential energy of the 
object is the same whether it is sitting on top of a post or suspended by 
a string from a balloon.  In either case, work was done on the body to get 
it a position above the earth.

The second half of your example describes the same body held at the same 
height by a rocket.  In this case you will need convert the potential 
energy of the rocket fuel into a force, (thrust) to hold the body up.  
SSince energy is being converted, the power (energy transfer/time) 
required to keep the body suspended must be determined.

I hope this is helpful.
Greg