You should select Choice-4 .
Answer:
2.7067 eV
Explanation:
h = Planck's constant = 
c = Speed of light = 
= Threshold wavelength = 459 nm
Work function is given by

Converting to eV


The work function W0 of this metal is 2.7067 eV
Answer: Several health conditions, your lifestyle, and your age and family history can increase your risk for heart disease. These are called risk factors. About half of all Americans (47%) have at least 1 of 3 key risk factors for heart disease: high blood pressure, high cholesterol, and smoking
Explanation: Have a great day!
To solve the exercise it is necessary to keep in mind the concepts about the ideal gas equation and the volume in the cube.
However, for this case the Boyle equation will not be used, but the one that corresponds to the Boltzmann equation for ideal gas, in this way it is understood that

Where,
N = Number of molecules
k = Boltzmann constant
V = Volume
T = Temperature
P = Pressure
Our values are given as,




Rearrange the equation to find V we have,



We know that length of a cube is given by

Therefore the Length would be given as,



Therefore each length of the cube is 3.44nm
Answer:
<em>The average speed is 22.2 km/h</em>
Explanation:
<u>Average Speed</u>
Given an object travels a total distance d and took a total time t, then the average speed is:

The mailman first drives d1=7 km at v1=15 km/h. The time taken to drive is:

Then he drives d2=7 km at v2=43 km/h taking a time of:

The total time is
t=0.467 h + 0.163 h = 0.63 h
The total distance is
d = 7 km + 7 km = 14 km
The average speed is:

The average speed is 22.2 km/h