Photoelectric Effect and the conversion ofPlank's constant from V.S to J.S

AI Thread Summary
The discussion focuses on calculating Planck's constant from a graph of cut-off voltage versus frequency. The slope of the graph, calculated as 4.224x10^-15 V.s, needs to be converted to J.s. The conversion involves using the equation eV = change in kinetic energy, as cut-off voltage represents the maximum kinetic energy of electrons. The relationship between the axes indicates that the gradient will yield the correct units for Planck's constant. Ultimately, the goal is to compare the calculated value with the accepted value of Planck's constant.
Hmpca
Messages
10
Reaction score
0
i graphed cut-off voltage verses frequency.
when i figured out plank's constant so when i calculated the slope of the function i got 4.224x10-15. My question is how to convert V.s to J.s for the value of hhereS the question

FINDING A VALUE OF PLANK'S CONSTANT FORM YOUR GRAPH.
calculate the slope of the graph (in V.s)
plank's constant is the slope of a graph of maximum kinetic evergy vs frequency so we need to convert cut-off coltage to maximum kinetic energy. we can use the equation.
eV=change in kinetic energy
because cut-off voltage just stops the most energetic electron.
convert the value of your slope to J.s and compare your value to the accepted value of plank's constant.
 
Physics news on Phys.org
If you have plotted KEmax against frequency the units on each axis should be eV (or maybe Joules) and s^-1 (frequency unit)
Can you see what units the gradient of a graph on these axes will be?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Photoelectric Effect Graph and Work Function Questions
Replies
25
Views
4K
Photoelectric effect calculation
Replies
8
Views
3K
Determining Planck's Constant With Photoelectric Effect
Replies
7
Views
5K
Photoelectric Effect - Laboration
Replies
1
Views
2K
I Photoelectric effect: Saturation voltage
Replies
4
Views
1K
Questions Regarding the Photoelectric Effect
Replies
11
Views
2K
The photoelectric effect report
Replies
1
Views
2K
Photoelectric Effect: Solving a Stopping Potential Problem
Replies
2
Views
2K
Photoelectric effect and work function
Replies
5
Views
11K
B Why is there now evidence of a lag time in the photoelectric effect?
Replies
10
Views
2K

Hot Threads

Recent Insights

Back
Top