That n2 = 2*n1. That is, the index of refraction is twice as big in medium 2 since v=c/n
They were going at a velocity 4.07m/s
<u>Explanation:</u>
Distance s =5 m
initial velocity u= 0.8 m/s
Acceleration a =1.6m/s2
We have to calculate the velocity with which they were going afterwards i.e final velocity.
Use the equation of motion

They were going with a velocity 4.07 m/s afterwards.
Explanation:
It is given that,
Velocity in East, 
Velocity in North, 
(a) The resultant velocity is given by :

(b) The width of the river is, d = 80 m
Let t is the time taken by the boat to travel shore to shore. So,


t = 16 seconds
(c) Let x is the distance covered by the boat to reach the opposite shore. So,


x = 48 meters
Hence, this is the required solution.
To solve this exercise it is necessary to apply the concepts related to Centripetal and Perimeter acceleration of a circle.
The perimeter of a circle is defined by

Where,
r= radius
While centripetal acceleration is defined by

Where,
v= velocity
r= radius
PART A)
The distance of a body can be defined based on the speed and the time traveled, that is
x = v*t
For our values the distance is equal to
x = 15*115=1725m
The plane when going to make the turn from east to south makes a quarter of the circumference that is

The same route you take is the distance traveled, that is




PART B)
With the radius is possible calculate he centripetal acceleration,



Therefore the radius of the curva that the plane follows in making the turn is 1098.17m with a centripetal acceleration of 
Answer:
the answer is 52.15cm×35.5