True. That is how powerful the sun is. But it will explode in only about 5 billion years.
        
             
        
        
        
Answer:
It cancels recoil.
Explanation:
For each action there is an equal an opposite reaction.
The principle of conservation of momentum tell us that if a single spore were ejected the fern would suffer a recoil from it. This recoil would take energy and speed from the spore. But if they are ejected in pairs the recoil is canceled and all the energy is transferred to the spores resulting in higher speeds.
 
        
             
        
        
        
Answer:
Part i)
h = 5.44 m
Part ii)
h = 3.16 m
Explanation:
Part i)
Since the ball is rolling so its total kinetic energy in this case will convert into gravitational potential energy
So we have

here we know that for spherical shell and pure rolling conditions






Part b)
If ball is not rolling and just sliding over the hill then in that case



 
        
             
        
        
        
Ocean waves travel through the medium called 
"ocean water" or "salt water" or simply "water".