500 N is the answer, you just tell that the moon is attracted towards the person because of the Earth's huge mass.
Answer:
(a) 
(b) 
(c)
(d)
Solution:
As per the question:
Refractive index of medium 1, 
Angle of refraction for medium 1, 
Angle of refraction for medium 2, 
Now,
(a) The expression for the refractive index of medium 2 is given by using Snell's law:

where
= Refractive Index of medium 2
Now,

(b) The refractive index of medium 2 can be calculated by using the expression in part (a) as:


(c) To calculate the velocity of light in medium 1:
We know that:
Thus for medium 1
(d) To calculate the velocity of light in medium 2:
For medium 2:
Answer:
Work done, W = -318.19 Joules
Explanation:
It is given that,
Force acting on the object, F = 50 N
Distance covered by the force, d = 9 m
Angle between the force and the distance traveled, 
The work done by an object is equal to the product of force and distance traveled. It is equal to the dot product of force and the distance. Mathematically, it is given by :


W = -318.19 Joules
So, the work done by the force is 318.19 Joules. The work is done in opposite to the direction of motion. Hence, this is the required solution.
Thermal energy is the answer
On ground weight of plane will be measured as its actual weight which will be given as

now when plane is in air its weight is measured as combined effect of earth gravitational force and buoyancy force both
so weight in air will be given as

here since net effect due to air is opposite to the direction of weight so in air the plane weight will be measure less than its weight on ground.
so answer will be
A)more than a plane in the air