Answer:
The time taken by missile's clock is 
Solution:
As per the question:
Speed of the missile, 
Now,
If 'T' be the time of the frame at rest then the dilated time as per the question is given as:
T' = T + 1
Now, using the time dilation eqn:




(1)
Using binomial theorem in the above eqn:
We know that:

Thus eqn (1) becomes:


Now, putting appropriate values in the above eqn:


let the distance of pillar is "r" from one end of the slab
So here net torque must be balance with respect to pillar to be in balanced state
So here we will have

here we know that
mg = 19600 N
Mg = 400,000 N
L = 20 m
from above equation we have



so pillar is at distance 10.098 m from one end of the slab
B. It reflects light rays outward.
A convex mirror looks like this ⊂. So when light rays hit the outward curves, it bends the light rays outwards, and backwards, and it would appear to be coming from its center called the focus.