Answer : First of all, to harness the solar energy and utilize it for the decomposition of water to make hydrogen fuel cell seems to be easy but practically it has many hurdles in its way. It might not work well, when the days would not be sunny. Also, the production of hydrogen fuel would require decomposing water which may need a high energy of activation, which would be more than the energy that will be produced from the fuel cell.
Answer:
Explanation:
Given
Weight of person 
At highest point Magnitude of the normal force 
net force at highest point
where 
centripetal force
Normal Force
Negative sign shows force is in upward direction
At bottom point centripetal force is towards the bottom
Answer:
option B
Explanation:
given,
Satellite B has an orbital radius nine times that of satellite A.
R' = 9 R
now, orbital velocity of the satellite A
........(1)
now, orbital velocity of satellite B
from equation 1
hence, the correct answer is option B
