Answer:
(A) Distance will be equal to 1.75 km
(B) Displacement will be equal to 1.114 km
Explanation:
We have given circumference of the circular track = 3.5 km
Circumference is given by 
r = 0.557 km
(a) It is given that car travels from southernmost point to the northernmost point.
For this car have to travel the distance equal to semi perimeter of the circular track
So distance will be equal to 
(b) If car go along the diameter of the circular track then it will also go from southernmost point to the northernmost point. and it will be equal to diameter of the track
So displacement will be equal to d = 2×0.557 = 1.114 m
Density is given by:
D = M/V
D = density, M = mass, V = volume
Given values:
M = 3.7g, V = 4.6cm³
Plug in and solve for D:
D = 3.7/4.6
D = 0.80g/cm³
Answer:
Length, l = 33.4 m
Explanation:
Given that,
Electrical field, 
Let the electrical potential is, 
We need to find the length of a thundercloud lightning bolt. The relation between electric field and the electric potential is given by :

So, the length of a thundercloud lightning bolt is 33.4 meters. Hence, this is the required solution.
Answer:
As the planets are very small and dark in comparison with stars, it makes them very hard to be found from earth.
Explanation:
Astronomy, of course, has a solution for this. As astronomers can't observe planets directly, they decided to observe the stars and search for the effects that planets have on them.
There are many ways of observing the exoplanets: Radial Velocity, Transit Photometry, Microlensing, Astrometry, Direct Imaging, etc.
Before all of this, scientist had to find ways to prove their theories. Most of their time they have spent in giving the creative answers.
Science and creativity are very much connected when we speak about the development of science. Rationality and creativity always go together.
In order to create an idea that other people will consider useful, it is important to use creativity. As no one has the exact answer when it comes to science, the adventure is to research the unknown.