Answer:
Albert Einstein was from Germany he was born theoritical physicist, from childhood only he loved mechanical toys, he was highly gifted in Mathematics, He was a world citizen and a scientific genius too. His contribution were:
1) he developed the theory of relativity
2) he also discovered the process of nuclear fission
3)he developed the quantum theory of specific heat
4)theory of stimulated emission, on which laser device technology is based
5) law of photoelectric effect
hope it helped you :)
Answer:
(i)
, (ii)
, (iii) 
Explanation:
(i)
and
represent the points where particle has a velocity of zero and spring reach maximum deformation, Given the absence of non-conservative force and by the Principle of Energy Conservation, the position where particle is at maximum speed is average of both extreme positions:

(ii) Maximum accelerations is reached at
and
.

(iii) Greatest net forces exerted on the particle are reached at
and
.

Periods<span> going left to right. The periodic table also has a special name </span>for<span> its vertical columns. Each column </span>is<span> called a </span>group. The elements in eachgroup<span> have the same number </span>of<span> electrons </span>in the<span> outer orbital.</span>