- #1

Stevee

- 8

- 0

## Homework Statement

A stopping potential of 0.50 V is required when a phototube is illuminated with monochromatic light of wavelength 600 nm. Monochromatic light of a different wavelength is now shone on the tube, and the stopping potential is measured to be 1.1V. What is the wavelength of this new light? (

*c*= 3.00 × 108 m/s, e = - 1.60 × 10-19 C,

*h*= 6.626 × 10-34 J · s, 1 eV = 1.60 × 10-19 J)

## Homework Equations

E=h*f (f=c/lambda)

h*f=sigma+Ek

## The Attempt at a Solution

E=h*c/lambda

lambda=h*c/E

I am just unsure on how to obtain the energy for the new monochromatic light given another.

Thankyou!