Answer:
n = 1.42
Explanation:
The refractive index for a medium is given by the ratio of the speed of light in vacuum to the speed of light in a medium.

So, the refractive index of the medium is 1.42.
That information describes the plane's speed.
If he had also told them what direction they were flying, then
they would have been able to put the two pieces of information
together, and they would know the plane's velocity.
Answer:
<h2>4.1 N</h2>
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 0.205 × 20
We have the final answer as
<h3>4.1 N</h3>
Hope this helps you
Answer:
Acceleration = Change in Velocity/Time
Change in Velocity = 36-18 = 18 km/h=5 m/s
Time= 5 Seconds
Acceleration = 5/5= 1 m/s2
Equation of motion,s=ut+(1/2)at2
u=18 km/h=5 m/s
t=5 s
a=1 m/s2
s= (5*5)+(1/2*1*5*5)
s=25+12.5 i.e., s=37.5 m
Hope you are clear with my explanations