Because different plants contain different vitamins and minerals as well as different amino acids and our body needs a large variety of these in order to preform all the necessary chemical reactions taking place inside our body. Some vegetables are very rich in a certain vitamin but are lacking in another, like how oranges have plenty of vitamin C but not iron. Vitamins and minerals are used in your cells to speed up and allow pretty much any chemical reaction to occur, but each one helps with a certain process and cannot simply be replaced by a different vitamin. In addition, very few vegetables contain all of the essential amino acids that work as the building blocks for protein synthesis and the creation of enzymes, so if you are not getting all of these in your diet, it is very unlikely you are producing enough enzymes and as a result certain functions in your body could stop working altogether.
(a) 6.04 rev/s
The speed of the ball is given by:

where
is the angular speed
r is the distance of the ball from the centre of the circle
In situation 1), we have

r = 0.600 m
So the speed of the ball is

In situation 2), we have

r = 0.900 m
So the speed of the ball is

So, the ball has greater speed when rotating at 6.04 rev/s.
(b) 
The centripetal acceleration of the ball is given by

where
v is the speed
r is the distance of the ball from the centre of the trajectory
For situation 1),
v = 30.6 m/s
r = 0.600 m
So the centripetal acceleration is

(c) 
For situation 2 we have
v = 34.1 m/s
r = 0.900 m
So the centripetal acceleration is

Answer:
due to production of heat through friction
1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:
