Solution: The correct order is: C, A, B
The statement of the problem:
How can we prove Earth is round and calculate its circumference?
Hypotheis:
If the sun casts shadows at different angles at the same time of day in different places, we can determine how much Earth curves.
If the Earth was flat, the angle measured at different places at the same time of the day would be same.
Observation:
In Syene, the sun's rays are vertical at noon. At the same time in Alexandria, the rays are 7.2 degrees from the vertical.
Electric field due to a charged rod along its axis is given by

here we know that
L = 14 cm
r = distance from end of rod
r = 36 - 7 = 29 cm
Q = 222 mC
now we will have


90 kilometers because you need to multiply 40 by 2 and then you get 80 and finally you add 10 and get 90 kilometers
Force = mass * acceleration
F = 15 *8 = 120 Newton