Answer:
part (a). 176580 J
part (b). 197381 J
Explanation:
Given,
- Density of the chain =

- Length of the chain = L = 60 m
- Acceleration due to gravity = g = 9.81

part (a)
Let dy be the small element of the chain at a distance of 'y' from the ground.
mass of the small element of the chain = 
Work done due to the small element,

Total work done to wind the entire chain = w

part (b)
- mass of the block connected to the chain = m = 35 kg
Total work done to wind the chain = work done due to the chain + work done due to the mass

The part of the electromagnetic spectrum has a shorter wavelength than ultraviolet light is x-rays.
(a) 392 N/m
Hook's law states that:
(1)
where
F is the force exerted on the spring
k is the spring constant
is the stretching/compression of the spring
In this problem:
- The force exerted on the spring is equal to the weight of the block attached to the spring:

- The stretching of the spring is

Solving eq.(1) for k, we find the spring constant:

(b) 17.5 cm
If a block of m = 3.0 kg is attached to the spring, the new force applied is

And so, the stretch of the spring is

And since the initial lenght of the spring is

The final length will be

Answer:
D. move up to another shell that would form
Explanation:
An atom has protons, neutrons and electrons. Protons and neutrons are present in the nucleus and electrons orbit the nucleus in fixed shells. An electron can jump to higher shell when it gains energy and lower one when it loses energy. Thus, when single electron in hydrogen atom is given a small amount of energy, it would jump to another higher shell.