<span>You may have noticed that there
are plants which do not have green leaves. Some plants are green because of a type of
pigment called chlorophyll. Plant cells
contain chloroplast which constitutes the pigment chlorophyll. Chlorophyll
absorbs red light and deep-blue light, hence, the rest of the sunlight spectrum
which is being reflected causes the plant to look green. When light reflects off on leaves into your eyes, the leaves take
in every hue of the rainbow, except for the color green, thus reflected into
your eyes and makes the leaves appear
green.</span>
Answer:
To increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.
Explanation:
First, we have to calculate the work function of the element. The maximum kinetic energy as a function of the wavelength is given by:
Here h is the Planck's constant, c is the speed of light, 
is the wavelength of the light and W the work function of the element:
Now, we calculate the wavelength for the new maximum kinetic energy:
This wavelength corresponds to ultraviolet radiation. So, to increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.
From the equestion:
I=V÷R
I=20÷100
I=0.2A
Answer:
Tangential acceleration is in the direction of velocity - along the circumference of a circle if the object is undergoing circular motion
a = (V2 - V1) / T
Radial acceleration is perpendicular to the direction of motion if the object is not moving in a straight line (perhaps along the circumference of a circle)
a = m V^2 / R = m ω^2 R where R is the radius vector of the velocity - note that the Radius vector is directed from the center of motion to the object and for circular motion would be constant in magnitude but not in direction
