The answer is 6 and a half days
Write the answer below the question?
Answer:
the final potential energy of this system is 3U0/10
Explanation:
We are given
charge at left end and another test charge at point p
Potential energy is given by =
where k is electrostatics constant = 
Q1 = first charge , Q2= test charge
R= distance between charges
potential at point p
U0 = k*Q1*Q2 /3 ⇒ kq1q2 = 3U0 ..............1
now the test charge moves to point R
using Pytahgoreou theorem
R(distance) =
= 10
New Potential energy
U1 = kq1*q2 / 10
substituting kq1q2 = 3U0 from 1
U1 = 3U0/10
So this is the final potential energy of this system.
Refractive index is the ration of sin i to sin r where i is the incident angle and r is the refraction angle.
Therefore, refractive index = sin 79.5 / sin 39.6
= 1.542
The refractive index may be given by the ratio of refractive index of medium 2 to refractive index of medium 1.
Therefore, 1.542 = n/1.0003
n = 1.5425
≈ 1.54
Medium 2 is sodium chloride, refractive index of 1.54
The impulse required to decrease the speed of the boat is equal to the variation of momentum of the boat:

where
m=225 kg is the mass of the boat

is the variation of velocity of the boat
By substituting the numbers into the first equation, we find the impulse:

and the negative sign means the direction of the impulse is against the direction of motion of the boat.