Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V
Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:
h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.
In order to calculate the cutoff wavelength we have to consider that Ek=0
in this case h*ν=W
(h*c)/λ=4.52 eV
λ= (h*c)/4.52 eV
λ= (1240 eV*nm)/(4.52 eV)=274.34 nm
From this h*ν = Ek+W; we can calculate the kinetic energy for a radiation wavelength of 198 nm
then we have
(h*c)/(λ)-W= Ek
Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV
Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this acts to slow down the ejected electrons from the catode.
Beats are interference patterns between two tones of different frequencies. To prove the skeptic first, play the recorded audio as there are no beats in it. Now take two sound sources with different frequencies. When both sources are turned on, we hear notes that rise and fall at equal intervals. That's what's called beats.
A frequency beat occurs when two waves with different frequencies overlap, causing alternating cycles of constructive and destructive interference between the waves.
When we tap the table with our finger, then put our ear to the table, and tap the table surface as far as 30 cm from our ear. Then the sound of beats on the table will sound louder when we put our ears on the table. So, it can be concluded that solid objects can conduct sound better than air. This is because the molecules or particles of solid objects are denser than air.
Learn more about the beat's frequency at brainly.com/question/14157895
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Answer:
The bullet's initial speed is 243.21 m/s.
Explanation:
Given that,
Mass of the bullet, 
Mass of the pendulum, 
The center of mass of the pendulum rises a vertical distance of 10 cm.
We need to find the bullet's initial speed if it is assumed that the bullet remains embedded in the pendulum. Let it is v. In this case, the energy of the system remains conserved. The kinetic energy of the bullet gets converted to potential energy for the whole system. So,
V is the speed of the bullet and pendulum at the time of collision
Now using conservation of momentum as :
Put the value of V from equation (1) in above equation as :
So, the bullet's initial speed is 243.21 m/s.
