Answer:

Explanation:
As we know that the speed of the rocket is v1 and v2 at the bottom and top of the window
then we will have



also we know that


now we have

also we have

now if the sill of the window is at height 8 m from the ground then we have



gravitational Potential energy is given by

here we have
m = 200 kg
h = 21000 m
now we will have


so GPE of balloon will be 41160000 J above the given height from ground
Yes,suns original energy are still stored at the bonds of fossils in which they taken long,long time ago and these fossils powered now industries,fuel for vehicles.In those chemical bonds holds much energy packed together for centuries.
Answer:
The final velocity of the wooden block is equal to 
Explanation:
Given that mass of bullet =
Mass of wood = 
Initial velocity of bullet = 
Final velocity of bullet = 
Initial velocity of wood = o
Final velocity of wood = ![v_{w]](https://tex.z-dn.net/?f=v_%7Bw%5D)
Here momentum is conserved so initial momentum = final momentum
.
Upon substituting these values in above equation , we get
.