Answer:
conserved
Explanation:
During this process the energy is conserved
Answer: A) 
Explanation:
The equation for the moment of inertia
of a sphere is:
(1)
Where:
is the moment of inertia of the planet (assumed with the shape of a sphere)
is the mass of the planet
is the radius of the planet
Isolating
from (1):
(2)
Solving:
(3)
Finally:
Therefore, the correct option is A.
As per energy conservation in the reversible engine we can say

here we know that


now from above equation


now we can convert it into kW


so above is the power input to the refrigerator
now to find COP we know that


so COP of refrigerator is 2.2
Answer:
A
Explanation:
Solution:-
- According to the law of relativity the relative speed between two moving objects is inversely proportional to the the time taken.
- Ignoring Doppler Effect.
- So if the relative speeds of two objects in motion i.e ( swing and spaceship) are positive then the time frame of reference for both object relative to other other decreases. So in other words if spaceship approaches the swing i.e relative velocity is positive then the time period of oscillation observed would be less than actual i.e less than 4 seconds.
- Similarly, if spaceship moves away from the swing i.e relative velocity is negative then the time period of oscillation observed would be more than actual i.e more than 4 seconds.