Answer:
(a) A = 
(b) 
(c) 
(d) 
Solution:
As per the question:
Radius of atom, r = 1.95
Now,
(a) For a simple cubic lattice, lattice constant A:
A = 2r
A = 
(b) For body centered cubic lattice:


(c) For face centered cubic lattice:


(d) For diamond lattice:


It will possibly be A) chemical b/c it can make a sound like when the bar hits the ball it makes a sound correct?! and also it created heat especially when it hits the ball. and when the ball MOVES and the bar HITS it creates kinetic energy, but when you hit the ball it doesn’t create a new substance.
“a point at which rays of light, heat, or other radiation meet after being refracted or reflected.” Meaning multiple light rays or heat (and other forms of radiation) are all being refracted or reflecting to a certain point
The formula for force exerted on/by a spring is
F = k*e where k is the spring constant and x is the distance stretched from
unstrained position. This should allow you to find what you need.
Using F = k x e,
where k is the spring constant,
and e is the extension,
The F is her weight = 45 X 0.80
= 36 N