Answer:
t = 3.29 seconds
Explanation:
It is given that,
Height of the Eiffel tower is 60 m
Initial speed of a euro, u = 2 m/s
It will move under the action of gravity in the downward direction. Firstly, we can find the final velocity as follows :

Let t is the time taken by the euro to hit the ground. It can be calculated as :

Hence, it will take 3.29 seconds to hit the ground.
0.4 N-s is the "impulse" acted on the "beach ball".
Option: C
Explanation:
Given that,
Mass of the "beach ball" is 0.1 kg.
The speed of the ball hits is 4 m/s.
We know that,
Whenever an object is collide with other object then an impulse is acted on object, this "impulse" causes "change in momentum".
Impulse acted on the beach ball is "mass" times "velocity".
Impulse = mass × velocity
Impulse = 0.1 × 4
Impulse = 0.4 kg m/s
Impulse = 0.4 N-s
Therefore, the "impulse" acted on the ball is 0.4 N-s.
The correct answer is
A. Chain reaction
This is how the chain reaction works in a process of nuclear fission:
1) Slow-moving neutrons reach heavy, unstable, radioactive nuclei (such as Uranium-235)
2) The neutrons interact with the nuclei of Uranium, which break apart producing smaller nuclei and additional neutrons
3) The neutrons produced in the reaction are slowed down by a moderator (e.g. water) and they interact with new nuclei of Uranium, causing new fission reactions)
4) The new neutrons interact with new nuclei of Uranium, and so on...