Answer:
material work function is 0.956 eV
Explanation:
given data
red wavelength 651 nm
green wavelength 521 nm
photo electrons = 1.50 × maximum kinetic energy
to find out
material work function
solution
we know by Einstein photo electric equation that is
for red light
h ( c / λr ) = Ф + kinetic energy
for green light
h ( c / λg ) = Ф + 1.50 × kinetic energy
now from both equation put kinetic energy from red to green
h ( c / λg ) = Ф + 1.50 × (h ( c / λr ) - Ф)
Ф =( hc / 0.50) × ( 1.50/ λr - 1/ λg)
put all value
Ф =( 6.63 ×
(3 ×
) / 0.50) × ( 1.50/ λr - 1/ λg)
Ф =( 6.63 ×
(3 ×
) / 0.50 ) × ( 1.50/ 651×
- 1/ 521 ×
)
Ф = 1.5305 ×
J × ( 1ev / 1.6 ×
J )
Ф = 0.956 eV
material work function is 0.956 eV
The correct answer should be C. Hydroelectric power stations can only produce enough energy for a small town as they do not produce large quantities
Hydroelectric power stations can power even large cities that have millions of people.
Answer:

Explanation:
The weight of an object on Earth is given by
, so we can calculate its mass by doing
, which for our values is:

<em>Nothing is being asked</em> about Io but if one wanted to know the weight <em>W'</em> of the watermelon there one just have to do:

Let the key is free falling, therefore from equation of motion
.
Take initial velocity, u=0, so
.

As velocity moves with constant velocity of 3.5 m/s, therefore we can use formula

From above substituting t,
.
Now substituting all the given values and g = 9.8 m/s^2, we get
.
Thus, the distance the boat was from the point of impact when the key was released is 10.60 m.
<em>Important thing is that all unitless quantity is dimensionless quantity. .</em><em>A</em><em> dimensionless physical quantity may have an unit</em>