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

[Hmpca]

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.

 

[technician]

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?